Electron paramagnetic resonance study of the singlet magnet KTb(WO4)2

Abstract

The electron paramagnetic resonance (EPR) spectrum of KTb(WO4)2 is investigated in the frequency range 14–120 GHz and magnetic field range 0–70 kOe at helium temperature. The observed triplet structure of the spectrum is interpreted as a manifestation of resonance in three-site clusters. On this basis a value of the g factor (g≈13.3) and an estimate of the gap (δ≈1 K) are obtained for the quasi-doublet ion Tb3+ in the crystalline field of KTb(WO4)2, and the parameters of the dipole (Id≈1.6 K) and exchange (Iex≈0.9 K) AFM interactions of the nearest neighbors in the chains are determined for the corresponding singlet magnet model. A first-order structural phase transition, induced by an external magnetic field lying in the basal plane of the crystal, is observed.

The EPR of monoclinic KY(WO4)2 single crystal doped with Sm3+ ion

“…to a temperature dependence of the g-factor. A similar variation of g-factor with temperature was reported earlier [10,11,14] [12] and Er 3+ [13]. Temperature change in the g-factor for the investigated Sm 3+ ions were not observed within the experimental error of measurements.…”

“…The EPR spectra of Gd 3+ [9], Dy 3+ [10], Er 3+ [11], Nd 3+ [12], Tb 3+ [13] and Yb 3+ [14] ions in magnetically diluted and concentrated double tungstate have all been thoroughly investigated. The rare earth ions are grouped in chains.…”

Magnetic properties of the strongly correlated chain antiferromagnet KTb(WO4)2

“…The ground state of Tb 3+ ion is 7F 6 with two singlets (quasi-doublet). The energy gap between singlets d % 1 K has been defined from frequency-field dependence of EPR spectrum of Tb 3+ in KTb(WO 4 ) 2 [1]. Existence of the three-dimensional magnetic ordering in a singlet magnet crucially depends on the ratio between energy gap and magnetic interaction values [2].…”

The low temperature magnetic properties of potassium holmium double tungstate

“…They are characterized by a strong magnetic anisotropy, low local symmetry, lowdimensional magnetic structure and exhibit strong spinlattice coupling [1][2][3][4][5][6][7][8][9]. The unusual physical properties of RE double tungstates are attributed by the partly filled 4 -electron shell of rare earth ions [10,11].…”