55 research outputs found
Theoretical and experimental study of high-pressure synthesized B20-type compounds Mn(Co,Rh)Ge
The search and exploration of new materials not found in nature is one of
modern trends in pure and applied chemistry. In the present work, we report on
experimental and \textit{ab initio} density-functional study of the
high-pressure-synthesized series of compounds Mn(Co,Rh)Ge. These
high-pressure phases remain metastable at normal conditions, therewith they
preserve their inherent noncentrosymmetric B20-type structure and chiral
magnetism. Of particular interest in these two isovalent systems is the
comparative analysis of the effect of (Co) and (Rh) substitution for
Mn, since the orbitals are characterized by higher localization and
electron interaction than the orbitals. The behavior of
Mn(Co,Rh)Ge systems is traced as the concentration changes in the
range . We applied a sensitive experimental and theoretical
technique which allowed to refine the shape of the temperature dependencies of
magnetic susceptibility and thereby provide a new and detailed
magnetic phase diagram of MnCoGe. It is shown that both systems
exhibit a helical magnetic ordering that very strongly depends on the
composition . However, the phase diagram of MnCoGe differs from
that of MnRhGe in that it is characterized by coexistence of two
helices in particular regions of concentrations and temperatures.Comment: 12 pages, 11 figure
Magnetocaloric effect in the high-temperature antiferromagnet YbCoC2
The magnetic - phase diagram and magnetocaloric effect in the recently
discovered high-temperature heavy-fermion compound YbCoC have been studied.
With the increase in the external magnetic field YbCoC experiences the
metamagnetic transition and then transition to the ferromagnetic state. The
dependencies of magnetic entropy change - have segments with
positive and negative magnetocaloric effects for ~T. For
~T magnetocaloric effect becomes positive with a maximum value of
- is 4.1 J / kg K and a refrigerant capacity is 56.6 J / kg
- …