Physics Commons^™

Exploring Tunable Magnetization And High-Temperature Ferromagnetism In Ternary Transition Metal-Based Chalcogenides, Hector Iturriaga

Open Access Theses & Dissertations

The discovery of long-range magnetic ordering in ultrathin transition metal-based compounds shows great promise for the development of nanoscale memory and spintronic devices. Composed of cost-effective materials and boasting from strong chemical and thermal stability at low dimensions, van der Waals (vdW) ternary transition metal chalcogenide magnets like CrSiTe3 (CST), Fe2.7GeTe2 (FGT), and Mn3Si2Te6 (MST), provide not only possible energy solutions, but also a broad platform to explore the versatile magnetic character of this family of compounds. Although they have great potential, it has been found that their long-range magnetic ordering exists at temperatures far too low (the highest of …

Evolution Of The Magnetic Properties On Van Der Waals Layered Magnets Via Pressure And Proton Irradiation, Rubyann Olmos

Open Access Theses & Dissertations

Probing the magnetism in quasi two-dimensional materials has the potential in driving their properties towards future use in spin electronic based devices. Studying such layered magnets will enable the scientific community to uncover tunable exotic phases such as superconductivity, quantum paramagnetism, etc. This work examines the influence of two types of external perturbations, namely, the pressure and proton irradiation, on the magnetic properties of several compounds in the van der Waals crystal family.

Pressure has been found to induce structural and magnetic phase transitions in many of these materials. Using hydrostatic pressure as a disorderless approach to manipulate the interlayer …

Investigation Of The Applicability Of Post-Irradiation Annealing To Reduce The Degree Of Disorder In Aln Ceramic To Proton Irradiation, A. L. Kozlovskiy

Eurasian Journal of Physics and Functional Materials

The work presents study results of the applicability of high-temperature heat treatment (500-700°C) of nitride ceramics irradiated with protons with an energy of 1.5 MeV and a dose of 10 16 cm ��2 . It was found that heat treatment for 60 minutes at a temperature of 700°C allows us to significantly reduce the density of radiation-induced defects and distortions in ceramics structure due to partial annihilation and relaxation of point defects. Dependences of changes in the strength and mechanical characteristics of ceramics on the temperature of post-irradiation annealing are shown. Based on the data obtained, a conclusion was made …

Development Of Software Tools And Experimental In Situ Electron Spin Resonance For Characterizing The Magnetic And Electrocatalytic Properties Of Transition Metal Chalcogenide Crystals, Jose Armando Delgado

Open Access Theses & Dissertations

Studying the magnetic properties and crystal defects of transition metal chalcogenide crystals is of paramount importance for utilizing them for next generation spintronics devices and hydrogen evolution reaction catalysts. Hydrothermally grown transition metal chalcogenide nanocrystals (MoS2, Ru2S3, Rh2S3, Co2S8) were chosen as catalysts for the hydrogen evolution reaction due to their low dimensionality and previous utilization as catalysts for hydrodesulfurization. The relationship between crystal defect sites and catalytic activity must be discerned to maximize the efficiency of hydrogen production during the hydrogen evolution reaction. ESR spectroscopy was utilized as a spin sensitive technique to study the defects and local changes …

The Effects Of Proton Irradiation On The Absorption Of Multi Component Glasses, Marcia Frances Bartusiak

Physics Theses & Dissertations

Three Schott glasses typically used in space technology -­ LaK 21, KzFS N4, and LF 5 -- were irradiated with 85 MeV protons. Induced absorption spectra were determined for each glass after varying fluences of radiation. It was found that the spectra for each glass can be fitted with three Gaussian shaped bands in the near ultraviolet-visible region, while a fourth Gaussian characterizes the absorption edge. For doses up to 10⁷ rads, the dependence of the induced absorption a on total dose is accurately described by the saturating exponential function a(Φ)= a_s (1 - e-^{-b Φ} ) …