Pressure-Induced Collapse of Magnetic Order in Jarosite.

We report a pressure-induced phase transition in the frustrated kagomé material jarosite at ∼45  GPa, which leads to the disappearance of magnetic order. Using a suite of experimental techniques, we characterize the structural, electronic, and magnetic changes in jarosite through this phase transition. Synchrotron powder x-ray diffraction and Fourier transform infrared spectroscopy experiments, analyzed in aggregate with the results from density functional theory calculations, indicate that the material changes from a R3[over ¯]m structure to a structure with a R3[over ¯]c space group.

An Isosymmetric High-Pressure Phase Transition in α-Glycylglycine: A Combined Experimental and Theoretical Study.

We investigated the effects of hydrostatic pressure on α-glycylglycine (α-digly) using a combined experimental and theoretical approach. The results of powder X-ray diffraction show a change in compressibility of the axes above 6.7 GPa, but also indicate that the structure remains in the same monoclinic space group, suggesting an isosymmetric phase transition.

Discovery of CuPb.

Materials discovery enables both realization and understanding of new, exotic, physical phenomena. An emerging approach to the discovery of novel phases is high-pressure synthesis within diamond anvil cells, thereby enabling in situ monitoring of phase formation. Now, the discovery via high-pressure synthesis of the first intermetallic compound in the Cu-Pb system, CuPb is reported.

Discovery of FeBi.

Recent advances in high-pressure techniques offer chemists access to vast regions of uncharted synthetic phase space, expanding our experimental reach to pressures comparable to the core of the Earth. These newfound capabilities enable us to revisit simple binary systems in search of compounds that for decades have remained elusive. The most tantalizing of these targets are systems in which the two elements in question do not interact even as molten liquids-so-called immiscible systems.

Discovery of a Superconducting Cu-Bi Intermetallic Compound by High-Pressure Synthesis.

A new intermetallic compound, the first to be structurally identified in the Cu-Bi binary system, is reported. This compound is accessed by high-pressure reaction of the elements. Its detailed characterization, physical property measurements, and ab initio calculations are described.

Mechanochemical Synthesis and High Temperature Thermoelectric Properties of Calcium-Doped Lanthanum Telluride LaCaTe.

The thermoelectric properties from 300 - 1275 K of calcium-doped LaTe are reported. LaTe is a high temperature n-type thermoelectric material with a previously reported zT ~ 1.1 at 1273 K and x = 0.

(BiSe)1.23CrSe2 and (BiSe)1.22(Cr1.2Se2)2: magnetic anisotropy in the first structurally characterized Bi-Se-Cr ternary compounds.

Compounds containing both heavy main group elements and paramagnetic transition metals form a fertile area for the study of magnetic anisotropy. We pursued the synthesis, characterization, and magnetic measurements of Bi-Se-Cr compounds: a ternary system with no structurally characterized materials. Those efforts led to the isolation of two novel misfit layer compounds, namely, (BiSe)1.