The hyperfine magnetic fields and the effect of high pressure on the magnetic transition temperatures of the noncentrosymmetric FeRhGecompound (B20).

Hyperfine parameters and the pressure dependence of the magnetic transition temperatures of FeRhGehave been investigated. Sample has been prepared using high pressure-high temperature synthesis technique. FeRhGeconsists of two B20 structure phases with close lattice constants.

Structural transformations and thermal stability of RhGe synthesized under high temperature and pressure.

Here, we study B20-type RhGe, a representative of a class of non-centrosymmetric monosilicides and monogermanides, which possess unique topological and magnetic properties important for many possible applications. The stability and phase transitions of the non-equilibrium B20-RhGe phase that can only be obtained under high pressure, are investigated theoretically usingcalculations and experimentally by means of differential scanning calorimetry. For RhGe and, for comparison, for its analogue RhSi, we conducted an evolutionary search for low-energy polymorphic modifications at zero temperature and then performed simulations of their behavior at finite temperatures.

High-pressure single-crystal synchrotron diffraction study of MnGe and related compounds.

Single crystal synchrotron diffraction for pressures up to 50 GPa has revealed an essential difference in structural properties and compressibility of MnGe compared with Mn Co Ge and Mn Fe Ge solid solutions. A negative thermal expansion has been observed for MnGe at low-temperatures and high-pressures. The single crystal refinement has shown a discontinuous change of the atomic coordinates and Mn-Ge interatomic distances of MnGe in contrast to MnCoGe.

Thermal expansion of monogermanides of 3d-metals.

Temperature dependent powder and single-crystal synchrotron diffraction, specific heat, magnetic susceptibility and small-angle neutron scattering experiments have revealed an anomalous response of MnGe. The anomaly becomes smeared out with decreasing Mn content in Mn1-x Co x Ge and Mn1-x Fe x Ge solid solutions. Mn spin state instability is discussed as a possible candidate for the observed effects.

Crystal structure and thermal expansion of Mn(1-x)Fe(x)Ge.

A series of temperature-dependent single-crystal and powder diffraction experiments has been carried out using synchrotron radiation in order to characterize the monogermanides of Mn, Fe and their solid solutions. The MnGe single crystal is found to be enantiopure and we report the absolute structure determination. The thermal expansion, parametrized with the Debye model, is discussed from the temperature-dependent powder diffraction measurements for Mn(1-x)Fe(x)Ge (x = 0, 0.