arXiv subjects

A. V. Bokov

Publications and source records attributed to A. V. Bokov.

4 recordsLinked to original sources

arXiv2026

The New High-entropy Compound RhMnFeCoGe4 with Cubic Non-centrosymmetric B20 Structure

A novel high-entropy compound, RhMnFeCoGe$_4$, with a cubic non-centrosymmetric B20 struc- ture, has been synthesized under conditions of high pressure and temperature. The electrical transport and magnetic properties of the obtained compound at both ambient and elevated pres- sures have been investigated. In addition, nuclear magnetic resonance (NMR) spectra were obtained at 4.2 K and ab initio calculations were performed. The new material exhibits ferromag- netic behavior with a critical temperature of $T_C$ = 146 K and a spontaneous moment of 2.5 $μ_B$ per formula unit. The magnetization data obtained at the critical region yielded the critical temperature and exponents, which were found to be $T_C$ = 146(1) K, $β$ = 0.337(1), $γ$ = 1.121(1), and $δ$ = 4.326(1). The magnetic moments of Mn and Co were determined from NMR spectra to be 2.2 $μ_B$ and 0.5 $μ_B$, respectively. Ab initio calculations yielded reasonable values for the lattice parameter and the magnetic moments of all constituents. The density of states and band structure are determined for both paramagnetic and ferromagnetic states. Lattice compression results in the increase in the $T_C$.

cond-mat.mtrl-sci↗

arXiv2026

SANS and magnetometry study of the magnetic phase diagram of the B20 helimagnet FeRhSi

This manuscript reports the first direct neutron-scattering evidence for long-period helimagnetism in the newly identified 4d-substituted B20 compound Fe0.5Rh0.5Si. By combining SANS with low-field magnetometry, we establish the magnetic modulation, construct a field-temperature phase diagram, and identify a candidate A-phase region supported by an independent structural signature. The work is important beyond this single compound because it expands the family of chiral B20 helimagnets into Rh-substituted materials, where spin-orbit coupling, disorder, and Dzyaloshinskii-Moriya interactions can be tuned. It will interest researchers in chiral magnetism, topological spin textures, magnetic neutron scattering, and quantum materials, and provides a foundation for future studies of emergent magnetic phases and topology-driven phenomena in chemically tuned chiral magnets.

cond-mat.str-el↗

arXiv2026

The analysis of heat capacity of MnGe metallic helimagnet

Zero-field heat capacity of metallic helimagnet MnGe was analyzed based on the results of resistivity decomposition published previously by our group for the same crystal. Current procedure allowed identifying along with ($i$) electronic ($\tildeγ$ $\approx$ 7 mJ/mol$\cdot$K$^2$) and ($ii$) phononic ($Θ_D$ $\approx$ 350 K) components ($iii$) the additional term, caused by the presence of spin fluctuations (SFs). The last contribution was found to exist in a wide range of temperatures in both paramagnetic (PM) and magnetically ordered states. However, its amplitude appears to be significantly lower in comparison with phononic component. The obtained value of spin fluctuation temperature $θ_{sf}$(MnGe) $\approx$ 330 K correlates well with previous estimations, as well as with results of various experiments, which predict the existence of SFs in MnGe at least up to 250 $-$ 300 K.

cond-mat.str-el↗

arXiv2023

Magnetocaloric effect in the high-temperature antiferromagnet YbCoC2

The magnetic $H$-$T$ phase diagram and magnetocaloric effect in the recently discovered high-temperature heavy-fermion compound YbCoC$_2$ have been studied. With the increase in the external magnetic field YbCoC$_2$ experiences the metamagnetic transition and then transition to the ferromagnetic state. The dependencies of magnetic entropy change -$ΔS_m (T)$ have segments with positive and negative magnetocaloric effects for $ΔH \leq 6$~T. For $ΔH = 9$~T magnetocaloric effect becomes positive with a maximum value of -$ΔS_m (T)$ is 4.1 J / kg K and a refrigerant capacity is 56.6 J / kg.

cond-mat.str-el↗