N.V. Mushnikov

Heterogeneous magnetic state of quasi-binary rare earth intermetallic compounds with CaCu5- and MgCu2-type structures

Abstract The magnetic properties of intermetallic R(Co 1− x Ni x ) 5 , with R ue5fb Sm and Gd, and Sm 1− x Tb x Fe 0.4 Co 1.6 compounds have been investigated. The temperature dependence of the ac susceptibility χ has a maximum at some temperature T = T C m (Hopkinsons effect). For binary compounds χ m = χ ( T C m ) = 1/ N , where N is the demagnetization factor, and in this case T C m corresponds to the Curie temperature. In quasi-binary compounds (0 x χ m N ) and χ m ( H ) ≠ const, and near T C m , χ ( T ) shows a temperature hysteresis. From the results obtained we conclude that the quasi-binary compounds are magnetically inhomogeneous, probably due to the existence of clusters in which the concentration x differs from stoichiometry.

Magnetic phase transitions in La1-xDyxMn2Si2 (0 ≤ x ≤ 1) compounds

Magnetic structures and properties of the quasi-ternary layered intermetallic La1-xDyxMn2Si2 (0 ? x ? 1) compounds were investigated using magnetic measurements on single crystals and neutron powder diffraction. It was shown that various magnetic structures and magnetic phase transitions, which are observed in the compounds with different Dy content, arise as result of changes in the intralayer Mn-Mn distances and competitions of the Mn-Mn, Mn-Dy and Dy-Dy exchange interactions.

Crossover from Valence Phase Transition to Kondo Behavior in Yb1-xCexInCu4 as Probed by Cu NQR

Influence of cerium substitution on the valence phase transition in Yb1-xCexInCu4 system (x = 0, 0.04, 0.08, 0.12 and 0.16) has been studied by means of 63Cu NQR. Discontinuous change in Cu NQR frequency was detected around valence transition temperature Tv in YbInCu4, Yb0.96Ce0.04InCu4 and Yb0.92Ce0.08InCu4. In the vicinity of Ce concentration x = 0.08 a crossover from the 1-st order valence phase transition to gradual change of electronic and magnetic properties of Yb1-xCexInCu4 system is observed.