TbxEr1−xNi5compounds: An ideal model system for competing Ising-

А. Н. Пирогов

¹

,

J.-G. Park

²

,

A. S. Ermolenko

³

et al.

Abstract

We have studied Tb x Er 1−x Ni 5 ͑x = 0, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 0.925, and 1.0͒ compounds by using several experimental techniques such as ac-susceptibility, heat-capacity, and neutron-diffraction measurements. All the compounds are found to crystallize in the CaCu 5 -type structure with space group P6 / mmm. The a axis shows a linear increase with Tb concentration, whereas the c axis remains almost unchanged over the whole doping range. Our neutron-diffraction studies revealed that samples for 0 Յ x Յ 0.8 have a commensurate magnetic structure with k = 0, whereas the two samples on the Tb-rich phase ͑x = 0.925 and 1.0͒ have an incommensurate structure. Of particular interest is that individual Tb and Er moments keep their mutually orthogonal arrangement seen at the end-member compositions over the whole doping range, due to very strong magnetic anisotropy of single-ion nature. We have established a complete magnetic x-T phase diagram of Tb x Er 1−x Ni 5 to find that two straight lines of the ordering of the Tb and Er subsystems are persistently seen, which intersect at a tetracritical point.

Strong anisotropy in the mixed antiferromagnetic system Mn1−xFexPSe3

“…Experimental evidence of such phases has been observed in the solid-solution intermetallic Tb x Er 1−x Ni 5 and ionic Fe 1−x Co x Cl 2 . 4,5 On the other hand, mixtures of antiferromagnets with different periodicities can form an intermediate phase with both magnetic orderings, as observed in Fe 1−x Mn x WO 4 . 6 A random magnet with competing interactions forms a disordered or spin glass state as observed in Mn 1−x Fe x PS 3 .…”

Electronic structure and optical spectroscopy studies of HoNi5 and ErNi5 compounds doped with Cu

“…Substitution of one R for the another rare earths and substitution of some of p‐ or d‐elements for Ni leads to modifications of magnetic and electronic characteristics owing to crystal field effects and changes of exchange interaction value between the conduction and 4f localized electrons. For example, a series of isostructural RNi 5− x Cu x alloys was found experimentally to have nonmonotonic concentration dependence of T C , magnetic susceptibility, electronic specific heat, and resistivity 5–9. Some published data indicate a direct correlation between such anomalies of physical properties and band structure transformation with a copper content increase 10–14.…”

Determining the magnetic ground state of TbNi5 single crystal using polarized neutron scattering technique

“…These two (partial depolarization and changes of magnetic moment components) factors can result in temperature dependencies, established in the experiment. We comment that none of three models proposed so far including ours has the collinear arrangement of ferromagnetic and modulated components [20]. Now we would like to consider an effect of an external magnetic field on the I off and I on intensities.…”