Ground State Properties of Tb³⁺Ion in TbNi₁₀Si₂

Abstract

Ground state properties of Tb3+ ion were investigated in the tetragonalT h Μ n h 1 2 -t y p e T b N i 1 0 S i 2 c o m p o u n d o n t l e b a s i s o f t e m p e r a t u r e d e p e n d e n c e of tle paramagnetic susceptibility and magnetization measurements. The rare earth temperature dependence of the susceptibility was calculated using the Van Vleck equation. The Γt5(1) doublet is suggested to be a ground state separated by 9 K from the first excited singlet Γ (12 ). The magnetic moment associated with the ground state doublet agrees with saturation magnetization data at 4.2 K. The overall crystal field splitting is estimated to be 105 K.PACS numbers: 75.30. Gw, 75.50.Gg The recent permanent magnet research stimulates investigations of various anisotropic iron-rich intermetallics. Among tlem there are compounds of the form RFe12 -x Τ (Τ = Ti, V, Cr, Mo, W and Si [1]) with tetragonal ThMn 1 2-type structure, which are isomorphous with non-magnetic RNi 1 0Si 2 series. The paramagnetic behaviour of the latter compounds is dominated by the crystal-field effects in the rare earth subsystem, since the magnetic moment at Ni sites is not significant [2]. The aim of the present paper is to investigate the crystal-field level structure of Tb3+ with the use of magnetic measurements in ΤbΝi 10 Si2 . The Ni subsystem can be considered as a Pauli paramagnet as already observed in ΥΝi10Si2 [3]. It is wort h noting that neutron spectroscopy measurements performed on a sample containing Tb [2] showed crystal-field level excitations that were not well resolved due to a complex level scheme.The method of preparation of ΤbNi 10Si 2 and YΝi 10 Si 2 has been described elsewhere [4]. The alloyed samples have been annealed for three weeks at 1100°C. Magnetic susceptibility measurements were carried out in the temperature range (281)

Crystal Field and Exchange Interactions in ThMn12-Type RZn12 Compounds (R = Tb, Tm)

“…The determined crystal field parameters B 0 2 and B 0 4 are one order of magnitude smaller than the parameters obtained for isostructural compounds RFe 12± ±x T x [2,3] and RNi 10 Si 2 [9,10]. One of the possible reasons of that fact is the difference of electronegativities of the surrounding environment of the rare earth ion.…”

“…Recently the RNi 10 Si 2 compounds have been investigated and attempts have been made to establish the rare earth ion ground state in these compounds with the use of neutron spectroscopy [8] and magnetic measurements [9,10].…”