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Full-Text Articles in Engineering
Ultrahigh Electromechanical Coupling And Its Thermal Stability In (Na1/2bi1/2)Tio3-Based Lead-Free Single Crystals, Chao Chen, Li Yang, Xingan Jiang, Xiaokun Huang, Xiaoyi Gao, Na Tu, Kaizheng Shu, Xiangping Jiang, Shujun Zhang, Haosu Luo
Ultrahigh Electromechanical Coupling And Its Thermal Stability In (Na1/2bi1/2)Tio3-Based Lead-Free Single Crystals, Chao Chen, Li Yang, Xingan Jiang, Xiaokun Huang, Xiaoyi Gao, Na Tu, Kaizheng Shu, Xiangping Jiang, Shujun Zhang, Haosu Luo
Australian Institute for Innovative Materials - Papers
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. In this work, we report the ultrahigh electromechanical coupling performance of NBT-6BT-KNN lead-free single crystal at room temperature. The thickness mode electromechanical coupling coefficient (kt) and the 31 mode electromechanical coupling coefficient (k31) reach 69.0% and 45.7%, respectively, which are superior to the PZT-5H lead-based ceramics of kt ~ 60% and k31~39%. In addition, the evolution of the crystal structure and domain morphology is revealed by Raman scattering spectra, a polarizing microscope and piezoelectric force microscopy characterization.
Study Of Flux Pinning Mechanism Under Hydrostatic Pressure In Optimally Doped (Ba,K)Fe2as2 Single Crystals, Babar Shabbir, Xiaolin Wang, Yanwei Ma, S X. Dou, Shi-Shen Yan, Liang-Mo Mei
Study Of Flux Pinning Mechanism Under Hydrostatic Pressure In Optimally Doped (Ba,K)Fe2as2 Single Crystals, Babar Shabbir, Xiaolin Wang, Yanwei Ma, S X. Dou, Shi-Shen Yan, Liang-Mo Mei
Australian Institute for Innovative Materials - Papers
Strong pinning depends on the pinning force strength and number density of effective defects. Using the hydrostatic pressure method, we demonstrate here that hydrostatic pressure of 1.2 GPa can significantly enhance flux pinning or the critical current density (Jc) of optimally doped Ba0.6K0.4Fe2As2 crystals by a factor of up to 5 in both low and high fields, which is generally rare with other Jc enhancement techniques. At 4.1 K, high pressure can significantly enhance Jc from 5 x 105 A/cm2 to nearly 106 A/cm2 at 2 T, and from 2 x 105 A/cm2 to nearly 5.5 x 105 A/cm2 at …
Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov
Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov
Australian Institute for Innovative Materials - Papers
The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon …
Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen
Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen
Australian Institute for Innovative Materials - Papers
Tremendous efforts towards improvement in the critical current density "Jc" of iron based superconductors (FeSCs), especially at relatively low temperatures and magnetic fields, have been made so far through different methods, resulting in real progress. Jc at high temperatures in high fields still needs to be further improved, however, in order to meet the requirements of practical applications. Here, we demonstrate a simple approach to achieve this. Hydrostatic pressure can significantly enhance Jc in NaFe0.97Co0.03As single crystals by at least tenfold at low field and more than a hundredfold at high fields. …
Super-Paramagnetic Particles Chemically Bound To Luminescent Diamond: Single Nano-Crystals Probed With Optically Detected Magnetic Resonance, Taras Plakhotnik, Haroon Aman, Shaohua Zhang, Zhen Li
Super-Paramagnetic Particles Chemically Bound To Luminescent Diamond: Single Nano-Crystals Probed With Optically Detected Magnetic Resonance, Taras Plakhotnik, Haroon Aman, Shaohua Zhang, Zhen Li
Australian Institute for Innovative Materials - Papers
We have synthesized novel composite particles made of single-domain nanomagnets chemically bound to nanocrystals of diamond. Optically detected magnetic resonance spectra of nitrogen-vacancy centers in diamond allowed us to estimate the magnetic field of the nanomagnets and to observe the saturation of their magnetization when an external field of a few tens of mT has been applied. The saturation effect is in agreement with the size of the domains measured using transmission electron microscopy and a simple model of magnetization.
Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu
Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu
Australian Institute for Innovative Materials - Papers
Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can …
Terahertz Probes Of Magnetic Field Induced Spin Reorientation In Yfeo 3 Single Crystal, Xian Lin, Junjie Jiang, Zuanming Jin, Dongyang Wang, Zhen Tian, Jiaguang Han, Zhenxiang Cheng, Guohong Ma
Terahertz Probes Of Magnetic Field Induced Spin Reorientation In Yfeo 3 Single Crystal, Xian Lin, Junjie Jiang, Zuanming Jin, Dongyang Wang, Zhen Tian, Jiaguang Han, Zhenxiang Cheng, Guohong Ma
Australian Institute for Innovative Materials - Papers
Using the terahertz time-domain spectroscopy, we demonstrate the spin reorientation of a canted antiferromagnetic YFeO3 single crystal, by evaluating the temperature and magnetic field dependence of resonant frequency and amplitude for the quasi-ferromagnetic (FM) and quasi-antiferromagnetic modes (AFM), a deeper insight into the dynamics of spin reorientation in rare-earth orthoferrites is established. Due to the absence of 4f-electrons in Y ion, the spin reorientation of Fe sublattices can only be induced by the applied magnetic field, rather than temperature. In agreement with the theoretical predication, the frequency of FM mode decreases with magnetic field. In addition, an …
Semimetal-Semiconductor Transition And Giant Linear Magnetoresistances In Three-Dimensional Dirac Semimetal Bi0.96sb0.04 Single Crystals, Zengji Yue, Xiaolin Wang, Shi-Shen Yan
Semimetal-Semiconductor Transition And Giant Linear Magnetoresistances In Three-Dimensional Dirac Semimetal Bi0.96sb0.04 Single Crystals, Zengji Yue, Xiaolin Wang, Shi-Shen Yan
Australian Institute for Innovative Materials - Papers
Three-dimensional (3D) Dirac semimetals are new quantum materials and can be viewed as 3D analogues of graphene. Many fascinating electronic properties have been proposed and realized in 3D Dirac semimetals, which demonstrate their potential applications in next generation quantum devices. Bismuth-antimony Bi1− x Sb x can be tuned from a topological insulator to a band insulator through a quantum critical point at x ≈ 4%, where 3D Dirac fermions appear. Here, we report on a magnetotransport study of Bi1− x Sb x at such a quantum critical point. An unusual magnetic-field induced semimetal-semiconductor phase transition was observed in the Bi0.96Sb0.04 …
Self-Growth Of Centimeter-Scale Single Crystals By Normal Sintering Process In Modified Potassium Sodium Niobate Ceramics, Cheol-Woo Ahn, Ho-Yong Lee, Guifang Han, Shujun Zhang, Si-Young Choi, Jong-Jin Choi, Jong-Woo Kim, Woon-Ha Yoon, Joon-Hwan Choi, Dong-Soo Park, Byung-Dong Hahn, Jungho Ryu
Self-Growth Of Centimeter-Scale Single Crystals By Normal Sintering Process In Modified Potassium Sodium Niobate Ceramics, Cheol-Woo Ahn, Ho-Yong Lee, Guifang Han, Shujun Zhang, Si-Young Choi, Jong-Jin Choi, Jong-Woo Kim, Woon-Ha Yoon, Joon-Hwan Choi, Dong-Soo Park, Byung-Dong Hahn, Jungho Ryu
Australian Institute for Innovative Materials - Papers
In this manuscript, an interesting phenomenon is reported. That is the self-growth of single crystals in Pb-free piezoelectric ceramics. These crystals are several centimeters in size. They are grown without any seed addition through a normal sintering process in modified potassium sodium niobate ceramics. It has been achieved by the composition designed to compensate the Na + loss which occurs during the liquid phase sintering. The composition of the crystals is (K0.4925 Na0.4925-x Ba0.015+x/2)Nb 0.995+x O3 [x is determined by the Na+ loss, due to Na2O volatilization]. These crystals have high piezoelectric voltage coefficients (g33, 131 10-3 Vm/N), indicating that …
Achieving Single Domain Relaxor-Pt Crystals By High Temperature Poling, Fei Li, Linghang Wang, Li Jin, Zhuo Xu, Shujun Zhang
Achieving Single Domain Relaxor-Pt Crystals By High Temperature Poling, Fei Li, Linghang Wang, Li Jin, Zhuo Xu, Shujun Zhang
Australian Institute for Innovative Materials - Papers
Single domain relaxor-PT crystals are important from both fundamental and application viewpoints. Compared to domain engineered relaxor-PT crystals, however, single domain crystals are prone to cracking during poling. In this paper, based on the analysis of the cracking phenomenon in [001] poled tetragonal 0.25Pb(In0.5Nb0.5)O3-0.37Pb(Mg 1/3Nb2/3)O3-0.38PbTiO3 (PIN-PMN-PT) crystals, the non-180°ferroelastic domain switching was thought to be the dominant factor for cracking during the poling process. A high temperature poling technique, by which the domain switching can be greatly avoided, was proposed to achieve the single domain relaxor-PT crystals. By this poling approach, a quasi-single domain crystal was obtained without cracks. In …
Hydrostatic Piezoelectric Properties Of [011] Poled Pb(Mg 1/3nb2/3)O3-Pbtio3 Single Crystals And 2-2 Lamellar Composites, Lili Li, Shujun Zhang, Zhuo Xu, Xuecang Geng, Fei Wen, Jun Luo, Thomas R. Shrout
Hydrostatic Piezoelectric Properties Of [011] Poled Pb(Mg 1/3nb2/3)O3-Pbtio3 Single Crystals And 2-2 Lamellar Composites, Lili Li, Shujun Zhang, Zhuo Xu, Xuecang Geng, Fei Wen, Jun Luo, Thomas R. Shrout
Australian Institute for Innovative Materials - Papers
The hydrostatic piezoelectric properties of [011] poled Pb(Mg 1/3Nb2/3)O3-PbTiO3 (PMN-PT) crystals and corresponding 2-2 crystal/epoxy composites were investigated. The crystal volume ratio and compositional dependencies of the hydrostatic charge and voltage coefficients (dh and gh) and hydrostatic figure of merit (FOM) dh x gh were determined, where large FOM value of 3.2 pm2/N with high stability as a function of hydrostatic pressure was achieved for rhombohedral crystal composites. In addition, the stress amplification effects of the face-plate and different epoxy matrixes were investigated, with maximum FOM value being on the order of 92 pm2/N, indicating that 2-2 crystal/epoxy composites are …
Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu
Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
Multi-layer graphene sheets have been synthesized by a time-efficient microwave autoclave method and used to form composites in situ with single-walled carbon nanotubes. The application of these composites as flexible free-standing film electrodes was then investigated. According to the transmission electron microscopy and X-ray diffraction characterizations, the average d-spacing of the graphene-single-walled carbon nanotube composites was 0.41 nm, which was obviously larger than that of the as-prepared pure graphene (0.36 nm). The reversible Li-cycling properties of the free-standing films have been evaluated by galvanostatic discharge-charge cycling and electrochemical impedance spectroscopy. Results showed that the free-standing composite film with 70 wt% …
A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu
A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g−1 after 40 cycles at a current density of 25 mA g−1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for …
Potential Advantage Of Multiple Alkali Metal Doped Knbo3 Single Crystals, Hideo Kimura, Hongyang Zhao, Rumi Tanahashi, Lei Guo, Tingting Jia, Qiwen Yao, Zhenxiang Cheng
Potential Advantage Of Multiple Alkali Metal Doped Knbo3 Single Crystals, Hideo Kimura, Hongyang Zhao, Rumi Tanahashi, Lei Guo, Tingting Jia, Qiwen Yao, Zhenxiang Cheng
Australian Institute for Innovative Materials - Papers
Potassium niobate crystal KNbO3 (KN) is a well-known crystal for lead free piezoelectric or nonlinear optical applications. The KN crystal has been studied in both single crystal form and in thin film form which has resulted in many review articles being published. In order to exceed the KN crystal, it is important to study KN phase forming and doping effects on the K site. This article summarizes the authors' study towards a multiple alkali metal doped KN crystal and related single crystals briefly from the viewpoint of crystal growth.
Cuo Single Crystal With Exposed {001} Facets-A Highly Efficient Material For Gas Sensing And Li-Ion Battery Applications, Dawei Su, Xiuqiang Xie, S X. Dou, Guoxiu Wang
Cuo Single Crystal With Exposed {001} Facets-A Highly Efficient Material For Gas Sensing And Li-Ion Battery Applications, Dawei Su, Xiuqiang Xie, S X. Dou, Guoxiu Wang
Australian Institute for Innovative Materials - Papers
Single crystal copper oxide nanoplatelets with a high percentage of {001} facets were synthesized by a facile hydrothermal approach. The as-prepared materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and high resolution transmission microscopy. Via density functional theory calculations, it was found that the {001} facets are active crystal planes. When the single crystal CuO nanoplatelets were applied as an anode material in Li-ion batteries, they demonstrated outstanding electrochemical performance with high lithium storage capacity, satisfactory cyclability, and excellent high rate capacity. When used as a sensing material in gas sensors, they exhibited …
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Australian Institute for Innovative Materials - Papers
This study addresses a combination of a well-developed and mild dispersion method and high-quality arc discharge single-walled carbon nanotubes (SWCNTs) as starting materials. Thus, we advance in fabrication of transparent, conducting films with extraordinary low material loss during SWCNT processing. The starting material was characterized by means of thermogravimetric analysis, high-resolution transmission electron microscopy and Raman spectroscopy. The quality of the starting material and produced dispersions was evaluated by ultraviolet and visible light absorption spectroscopy and Raman spectroscopy. A transparent conductive film was fabricated by drop-casting, whereas films were obtained with electrical to optical conductivity ratios (σDC/σOp) as high as …
Performance Enhancement Of Single-Walled Nanotube-Microwave Exfoliated Graphene Oxide Composite Electrodes Using A Stacked Electrode Configuration, Dennis Antiohos, Mark S. Romano, Joselito M. Razal, Stephen Beirne, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Jun Chen
Performance Enhancement Of Single-Walled Nanotube-Microwave Exfoliated Graphene Oxide Composite Electrodes Using A Stacked Electrode Configuration, Dennis Antiohos, Mark S. Romano, Joselito M. Razal, Stephen Beirne, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Jun Chen
Australian Institute for Innovative Materials - Papers
We report the development of a stacked electrode supercapacitor cell using stainless steel meshes as the current collectors and optimised single walled nanotubes (SWNT)-microwave exfoliated graphene oxide (mw rGO) composites as the electrode material. The introduction of mw rGO into a SWNT matrix creates an intertwined porous structure that enhances the electroactive surface area and capacitive performance due to the 3-D hierarchical structure that is formed. The composite structure was optimised by varying the weight ratio of the SWNTs and mw rGO. The best performing ratio was the 90% SWNT-10% mw rGO electrode which achieved a specific capacitance of 306 …
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
In this report single-wall carbon nanotubes (SWNTs) were coated onto latex using spray coating to produce a stretchable electrode. The electrochemical properties of the electrode were determined using cyclic voltammetry and electrochemical impedance spectroscopy and galvanostatic charge/discharge tests were also carried out. The impedance and charge/discharge curves of the latex/SWNTs electrode showed good capacitive behavior even after repetitive stretching to 100% strain. The highest capacitance value obtained for the unstretched SWNTs electrode was 119 F g−1 in 1 M Na2SO4 at 5 mV s−1. After the 100th stretch ≈ 80% of the original capacitance value was retained.
Single Crystalline Co3o4 Nanocrystals Exposed With Different Crystal Planes For Li-O2 Batteries, Dawei Su, S X. Dou, Guoxiu Wang
Single Crystalline Co3o4 Nanocrystals Exposed With Different Crystal Planes For Li-O2 Batteries, Dawei Su, S X. Dou, Guoxiu Wang
Australian Institute for Innovative Materials - Papers
Single crystalline Co3O4 nanocrystals exposed with different crystal planes were synthesised, including cubic Co3O4 nanocrystals enclosed by {100} crystal planes, pseudo octahedral Co3O4 enclosed by {100} and {110} crystal planes, Co3O4 nanosheets exposed by {110} crystal planes, hexagonal Co3O4 nanoplatelets exposed with {111} crystal planes, and Co3O4 nanolaminar exposed with {112} crystal planes. Well single crystalline features of these Co3O4 nanocrystals were confirmed by FESEM and HRTEM analyses. The electrochemical performance for Li-O2 batteries shows that Co3 …
Single-Pulse Terahertz Coherent Control Of Spin Resonance In The Canted Antiferromagnet Yfeo3, Mediated By Dielectric Anisotropy, Zuanming Jin, Zoltan Mics, Guohong Ma, Zhenxiang Cheng, Mischa Bonn, Dmitry Turchinovich
Single-Pulse Terahertz Coherent Control Of Spin Resonance In The Canted Antiferromagnet Yfeo3, Mediated By Dielectric Anisotropy, Zuanming Jin, Zoltan Mics, Guohong Ma, Zhenxiang Cheng, Mischa Bonn, Dmitry Turchinovich
Australian Institute for Innovative Materials - Papers
We report on the coherent control of terahertz (THz) spin waves in a canted antiferromagnet yttrium orthoferrite, YFeO3, associated with a quasiferromagnetic (quasi-FM) spin resonance at a frequency of 0.3 THz, using a single-incident THz pulse. The spin resonance is excited impulsively by the magnetic field component of the THz pulse. The intrinsic dielectric anisotropy of YFeO3 in the THz range allows for coherent control of both the amplitude and the phase of the excited spin wave. The coherent control is based on simultaneous generation of two interfering phase-shifted spin waves whose amplitudes and relative phase, dictated by the dielectric …
The Flux Pinning Mechanism, And Electrical And Magnetic Anisotropy In Fe1.04te0.6se0.4 Superconducting Single Crystal, Mahboobeh Shahbazi-Manshadi, Xiaolin Wang, S X. Dou, H Fang, C T. Lin
The Flux Pinning Mechanism, And Electrical And Magnetic Anisotropy In Fe1.04te0.6se0.4 Superconducting Single Crystal, Mahboobeh Shahbazi-Manshadi, Xiaolin Wang, S X. Dou, H Fang, C T. Lin
Australian Institute for Innovative Materials - Papers
The temperature and magnetic field dependences of the magnetization and critical current density of Fe1.04Te0.6Se0.4 single crystals have been investigated, and the flux pinning mechanism has been analysed. The normalized pinning force (fp Fp/F p,max) vs. h(H/Hirr) curves, are scaled using the Dew-Hughes theory, f(h) ≈ hp(1 - h)q with p 1.35 and q 3.06. The angular dependence of the resistivity under different magnetic fields shows a dip-like structure, below the superconducting transition temperature. The anisotropic value of 2 was obtained using Ginzburg-Landau theory.
Spin Switching And Magnetization Reversal In Single-Crystal Ndfeo3, S J. Yuan, W Ren, F Hong, Y B. Wang, J C. Zhang, L Bellaiche, S X. Cao, G Cao
Spin Switching And Magnetization Reversal In Single-Crystal Ndfeo3, S J. Yuan, W Ren, F Hong, Y B. Wang, J C. Zhang, L Bellaiche, S X. Cao, G Cao
Australian Institute for Innovative Materials - Papers
We report an experimental and computational study of single-crystal NdFeO3, which features two inequivalent magnetic sublattices, namely, Fe and Nd sublattices that are coupled in an antiparallel fashion. This paper reveals that a strong interaction between 3d and 4f electrons of the two sublattices along with a spin-lattice coupling drives an extremely interesting magnetic state that is highly sensitive to the orientation and history of weak magnetic field. The following phenomena are particularly remarkable: (1) sharply contrasting magnetization M(T) along the a and c axes; (2) a first-order spin switching along the a axis below 29 K when the system …
Direct Observation Of Liquid-Like Behavior Of A Single Au Grain Boundary, Gilberto Casillas, Arturo Ponce, Jesus Velazquez-Salazar, M Jose-Yacaman
Direct Observation Of Liquid-Like Behavior Of A Single Au Grain Boundary, Gilberto Casillas, Arturo Ponce, Jesus Velazquez-Salazar, M Jose-Yacaman
Australian Institute for Innovative Materials - Papers
Behavior of matter at the nanoscale differs fromthat of the bulk due to confinement and surface effects. Here, we report a direct observation of liquid-like behavior of a single grain boundary formed by cold-welding Au nanoparticles, 40 nm in size, by mechanical manipulation in situ TEM. The grain boundary rotates almost freely due to the free surfaces and can rotate about 90 degrees. The grain boundary sustains more stress than the bulk, confirming a strong bonding between the nanoparticles.Moreover, this technique allows the measurement of the surface diffusion coefficient from experimental observations, which we compute for the Au nanoparticles. This …
Platinum Electrodeposition On Unsupported Single Wall Carbon Nanotubes And Its Application As Methane Sensing Material, Enid Contes-De Jesus, Diana Santiago, Gilberto Casillas, Alvaro Mayoral, Cesar Magen, Miguel Jose-Yacaman, Jing Li, Carlos R. Cabrera
Platinum Electrodeposition On Unsupported Single Wall Carbon Nanotubes And Its Application As Methane Sensing Material, Enid Contes-De Jesus, Diana Santiago, Gilberto Casillas, Alvaro Mayoral, Cesar Magen, Miguel Jose-Yacaman, Jing Li, Carlos R. Cabrera
Australian Institute for Innovative Materials - Papers
This paper reports the decoration of single wall carbon nanotubes (SWCNTs) with platinum (Pt) nanoparticles using an electrochemical technique, rotating disk slurry electrode (RoDSE). Pt/SWCNTs were electrochemically characterized by cyclic voltammetry technique (CV) and physically characterized through the use of transmission electron microscopy (TEM), energy dispersive spectroscopy - X-ray florescence (EDS-XRF) and X-ray diffraction (XRD). After characterization it was found that electrodeposited nanoparticles had an average particle size of 4.1 ± 0.8 nm. Pt/SWCNTs were used as sensing material for methane (CH4) detection and showed improved sensing properties in a range of concentration from 50 ppm to 200 ppm parts …
Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou
Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou
Australian Institute for Innovative Materials - Papers
The flux pinning mechanism of BaFe1.9Ni0.1As2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, Jc, was analysed within the collective pinning model. A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe1.9Ni0.1As2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, Fp, curves versus h1/4B/Birr (Birr is the irreversibility field) were scaled using the Dew-Hughes model. Analysis suggests that point pinning alone cannot explain the observed …
Magnetic Field Induced Discontinuous Spin Reorientation In Erfeo3 Single Crystal, Hui Shen, Zhenxiang Cheng, Fang Hong, Jiayue Xu, Shujuan Yuan, Shixun Cao, Xiaolin Wang
Magnetic Field Induced Discontinuous Spin Reorientation In Erfeo3 Single Crystal, Hui Shen, Zhenxiang Cheng, Fang Hong, Jiayue Xu, Shujuan Yuan, Shixun Cao, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
The spin reorientation of ErFeO3 that spontaneously occurs at low temperature has been previously determined to be a process involving the continuous rotation of Fe3þ spins. In this work, the dynamic process of spin reorientation in ErFeO3 single crystal has been investigated by AC susceptibility measurements at various frequencies and static magnetic fields. Interestingly, two completely discontinuous steps are induced by a relatively large static magnetic field due to the variation in the magnetic anisotropy during this process. It provides deeper insights into the intriguing magnetic exchange interactions which dominate the sophisticated magnetic phase transitions in the orthoferrite systems.
Crystal Growth, Structure And Thermal Properties Of Noncentrosymmetric Single Crystals Prca4o(Bo3)3+, Fapeng Yu, Shujun Zhang, Xiufeng Cheng, Xiulan Duan, Tingfeng Ma, Xian Zhao
Crystal Growth, Structure And Thermal Properties Of Noncentrosymmetric Single Crystals Prca4o(Bo3)3+, Fapeng Yu, Shujun Zhang, Xiufeng Cheng, Xiulan Duan, Tingfeng Ma, Xian Zhao
Australian Institute for Innovative Materials - Papers
Noncentrosymmetric praseodymium calcium oxyborate single crystals, PrCa4O(BO3)3 (PrCOB), were grown by the Czochralski technique. The monoclinic unit cell parameters were found to be a = 8.177 Å, b = 16.157 Å, c = 3.629 Å and Z = 2 with space group Cm. Crystal density was measured using the Archimedes method, being on the order of 3.47 g cm-3. Thermal properties of PrCOB were investigated, where the specific heat was found to be 0.63 J g-1 °C-1 at room temperature, increasing to 0.85 J g-1°C-1 at 700°C. The thermal expansion coefficients were measured to be α11 = 7.99, α22 = …
Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue
Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue
Australian Institute for Innovative Materials - Papers
Low-temperature scanning tunneling microscope (STM) is exploited to study directly the atomic and electronic structures of single Fe dopants in topological insulator Bi2Se3 thin films. Fe atoms predominantly and isovalently substitute for two distinct Bi sites at the subsurface with charge neutrality. In the vicinity of Fe substitutions, circular depressions in STM topography and sharp rings in spatially resolved conductance map, whose diameters apparently depend on the tunneling conditions, are observed. We show that the phenomena correlate well with the switching between Fe3+ and Fe2+ charge states due to the gate effect of the tunneling tip, as further evidenced by …
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Australian Institute for Innovative Materials - Papers
Magnetic properties and the magnetocaloric effect (MCE) have been investigated in La0.7Ca0.3MnO3 single crystal with applied field along both the ab-plane and the c-direction. Due to the magnetocrystalline anisotropy, the crystal exhibits anisotropy in the MCE. Upon application of a 5 T field, the magnetic entropy changes (SM), reaching values of 7.668 J/(kg K) and 6.412 J/(kg K) for both the ab-plane and the c-direction, respectively. A magnetic entropy change of 3.3 J/(kg K) was achieved for a magnetic field change of 1.5 T at the Curie temperature, TC = 245 K. Due to the absence of grains in the …
Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou
Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou
Australian Institute for Innovative Materials - Papers
Polycrystalline (PC) and single crystalline (SC) samples of La0.7Ca0.3CoO3 (LCCO) with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We conducted isothermal magnetization measurements of the PC and SC samples at temperatures from 2.8 K to 140 K, and evaluated the magnetic entropy change (−ΔSM) under zero field cooling (ZFC) and field cooling (FC) to 2.8 K. An interesting result has been obtained, where the −ΔSM–T curves in the low temperature range show totally different features between the ZFC and FC cooling procedures. The −ΔS …