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Physical Sciences and Mathematics Commons

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Engineering

University of Wollongong

Series

2008

Doped

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Structure, Ferroelectric Properties, And Magnetic Properties Of The La-Doped Bismuth Ferrite, Zhenxiang Cheng, Aihua Li, Xiaolin Wang, S X. Dou, Kiyoshi Ozawa, Hideo Kimura, S Zhang, Thomas R. Shrout Jan 2008

Structure, Ferroelectric Properties, And Magnetic Properties Of The La-Doped Bismuth Ferrite, Zhenxiang Cheng, Aihua Li, Xiaolin Wang, S X. Dou, Kiyoshi Ozawa, Hideo Kimura, S Zhang, Thomas R. Shrout

Australian Institute for Innovative Materials - Papers

Bi1-xLaxFeO3 ceramics with x=0, 0.1, 0.2, and 0.3 have been synthesized by solid state reaction, starting from metal oxides. A series of structure transformations is found to depend upon the doping level. Below 10% La doping, Bi1-xLaxFeO3 maintains the rhombohedral structure of BiFeO3. However, for Bi0.8La0.2FeO3 and Bi0.7La0.3FeO3, the structures change to the orthorhombic and tetragonal, respectively. La doping significantly reduces electric leakage and leads to successful observation of electrical polarization hysteresis loops. Doping with La also …


Correlation Between Doping Induced Disorder And Superconducting Properties In Carbohydrate Doped Mgb2, Jung Ho Kim, S X. Dou, Sangjun Oh, M Jercinovic, E Babic, T Nakane, Hiroaki Kumakura Jan 2008

Correlation Between Doping Induced Disorder And Superconducting Properties In Carbohydrate Doped Mgb2, Jung Ho Kim, S X. Dou, Sangjun Oh, M Jercinovic, E Babic, T Nakane, Hiroaki Kumakura

Australian Institute for Innovative Materials - Papers

A comprehensive study of the effects of carbohydrate doping on the superconductivity of MgB2 has been conducted. In accordance with the dual reaction model, more carbon substitution is achieved at lower sintering temperature. As the sintering temperature is lowered, lattice disorder is increased. Disorder is an important factor determining the transition temperature for the samples studied in this work, as evidenced from the correlations among the lattice strain, the resistivity, and the transition temperature. It is further shown that the increased critical current density in the high field region can be understood by a recently-proposed percolation model [M. Eisterer …


Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain Jan 2008

Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain

Australian Institute for Innovative Materials - Papers

Flux-pinning mechanism of MgB2 doped with 10 wt % silicone-oil sintered at low and high temperatures has been investigated by magnetic measurements. The field dependence of the critical current density, jc(B), was analysed within the collective pinning model. A crossover field, Bsb, from the single vortex to the small vortex bundle-pinning regime was observed. For both types of sintered samples, the temperature dependence of Bsb(T) at low temperature is in good agreement with the δl pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. At temperatures close to the critical …


Dielectric, Magnetic, And Magnetotransport Properties In Sr Doped Two-Dimensional Re2coo4 (Re=Pr,Eu) Compounds, Qiwen Yao, Xiaolin Wang, S X. Dou Jan 2008

Dielectric, Magnetic, And Magnetotransport Properties In Sr Doped Two-Dimensional Re2coo4 (Re=Pr,Eu) Compounds, Qiwen Yao, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

In this work, we report on the studies of dielectric, magnetic, and magnetotransport properties of Sr doped RE2-xSrxCoO4 (RE=Pr or Eu, x=0.25-1.5). These compounds were systematically studied in terms of structure, magnetic, magnetotransport, and dielectric constant measurements. Rietveld refinement indicated that these compounds crystallized in K2NiF4-type structure with space group I4/mmm. Lattice parameters increase with Sr doping level. The system changes from paramagnetic to ferromagnetic with increasing Sr doping level and finally becomes ferromagnetic with TC of 230 K for Pr0.75Sr1.25CoO4 and …


Enhancement Of Ferroelectricity And Ferromagnetism In Rare Earth Element Doped Bifeo3, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa Jan 2008

Enhancement Of Ferroelectricity And Ferromagnetism In Rare Earth Element Doped Bifeo3, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa

Australian Institute for Innovative Materials - Papers

Rare earth element doped BiFeO3 thin films were fabricated using the pulsed laser deposition method and various targets made from different starting Fe2O3 and Fe3O4 iron source materials. The films fabricated using the targets made from Fe3O4 exhibit great enhancement in their ferroelectricity, due to greatly reduced electrical leakage, as well as enhanced magnetization compared to those films deposited using targets from Fe2O3. It is suggested that the Fe2+ ion plays an important role in compensating for the charge imbalance and reducing current leakage, as …


High Field Performance Of Nano-Diamond Doped Mgb2 Superconductor, Arpita Vajpayee, V P. Awana, H Kishan, Anant Narlikar, G L. Bhalla, Xiaolin Wang Jan 2008

High Field Performance Of Nano-Diamond Doped Mgb2 Superconductor, Arpita Vajpayee, V P. Awana, H Kishan, Anant Narlikar, G L. Bhalla, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

The results from magnetotransport and magnetization of nanodiamond doped MgB2-nDx are reported. Superconducting transition temperature (Tc) is not affected significantly by x up to x =0.05 and latter decreases slightly for higher x>0.05. R(T) vs H measurements show higher Tc values under same applied magnetic fields for the nanodiamond added samples, resulting in higher estimated Hc2 values. From the magnetization measurements, it was found that irreversibility field value Hirr for the pristine sample is 7.5 T at 4 K and the same is increased to 13.5 T for 3 wt % …