Physics Commons^™

X-Ray Diffraction Study Of Dysprosium Single Crystal Samples In A Diamond Anvil Cell (Dac), Ognjen Grubor-Urosevic

UNLV Theses, Dissertations, Professional Papers, and Capstones

X-ray diffraction is the basis of crystallography, the study of the structure of crystals. It uses X-rays of a wavelength on the order of the size of atoms, so it can resolve the positions of individual atoms in a crystal. Illuminating the crystal with a well-collimated X-ray beam produces X-rays diffracted in a certain direction for a specific crystal orientation. By analyzing the relative phase of the incoming and outgoing scattered X-rays, the unique arrangements of atoms can be determined and the structure of the crystal can be solved.

There is a long standing controversy regarding the crystal structures and …

Ac Susceptibility And Heat Capacity Studies Of The Geometrically Frustrated Pyrochlores Terbium Titanium Tin Oxides And Holmium Titanates, Daniel Antonio

UNLV Theses, Dissertations, Professional Papers, and Capstones

Materials with a geometrically frustrated magnetic pyrochlore lattice have been of interest due to their unusual ground states. Tb 2 Ti 2 O 7 is known for having a spin liquid ground state which does not transition to a long-range ordered state down to at least 50 mK. Ho 2 Ti 2 O 7 has a macroscopically degenerate spin ice ground state which resembles that of the proton ordering in water ice. Heat Capacity measurements of Tb 2 Ti 2- x Sn x O 7 were done down to 0.36 K and AC magnetic susceptibility measurements of Ho 2- x …

High Pressure Phase Transistions In The Lanthanide Sesquioxides, Jason Patrick Mcclure

UNLV Theses, Dissertations, Professional Papers, and Capstones

Crystallizing into 5 known polymorphic forms, the rare-Earth sesquioxides RE 2 O 3 represent a family of 4-f electron compounds that have been the subject of study for many years. Aspects of the systematics in the structural phase transitions for RE 2 O 3 (RE=La, Sm, Eu, Gd, Y, Er, Yb, Lu) under pressure were studied using diamond anvil cells (DACs). As a part of this study, detailed equation of state (EOS) data for all these compounds were obtained through the use of angle-dispersive x-ray diffraction (XRD) where anomalies in compression data led to the detailed investigation into one particular …

Static High Pressure Ft-Ir Spectroscopic Studies Of Tatb, Brian F. Yulga

UNLV Theses, Dissertations, Professional Papers, and Capstones

Static high-pressure experiments utilizing diamond anvil cells (DACs) provide an alternative method to shockwave studies for extracting precise information on the physical and chemical properties of energetic materials. Due to mechanical restraints (e.g. small sample sizes and apertures), synchrotron radiation sources are ideal for probing the structure of materials at the molecular level. 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is an insensitive (tertiary) high explosive (iHE) useful in military applications. Compared to other conventional iHEs, it is a safer and more stable energetic material. Its unique properties cause it to be of interest in the energetic materials research community. A series of Fourier-transform infrared …