Temperature Variation of EPR Linewidth of Gd³⁺ and Estimation of Spin–Lattice Relaxation Time of Nd³⁺ in NdF₃ Single Crystals

Abstract

EPR (X-band) linewidths of the Gd3+ ion in NdF, and LaF, single crystals in the temperature range 140 to 510 K are investigated. The mechanism of spin--lattice modulated narrowing is adapted to explain the temperature dependence of the G d 3 + EPR linewidths in the presence of the Kramers host Nd3+ ions (4f3, 419,r). The spin-lattice relaxation time (z;) of the host ions Nd3+ in Gd3+-doped NdF, single crystal is calculated, using the equation for crystals containing two different species of paramagnetic ions.On a etuditi des largeurs des raies de la RPE (bande X) de l'ion Gd3+ dans des monocristaux NdF, et LaF, dans un intervalle de temperature de 140 a 510 K. Un modele de la contraction modulee spin-reseau a ete adopt6 afin d'expliquer la dependence des largeurs de la raie de la RPE de Pion Gd3 + de la temperature en presence des ions h6tes de Kramers Nd3+ (4f3, '19,J. Au moyen de I'equation pour le cristal contenant des ions paramagnetique differents, on a calculi. le temps de relaxation spin-reseau (7;) des ions h6tes Nd3+ dans le cristal NdF, dope par des ions Gd3+.

Spin-Lattice Relaxation and Superposition Model Calculation in Gd3+-Doped LiErF4and LiDyF4Crystals

“…The calculated relaxation time of LiErF4 (1.0 x 10 -15 s) is slightly different from those of LiDyF4 (2.7 x 10 -15 s) and LiYbF4* (2.2 x 10 -15 s). In case of different crystal families and various RE 3 + ions, SLRT also does not differ significantly, e.g., for Gd 3 +-doped NdF3 crystal τ1'(Nd) = 1.7 x 10 -15 s [35].…”

“…The corrected values of SLRT (Nd3 +) in [35] are alinost contained in error bars, e.g., for the 5/2 3/2 transition τ'1(Nd) is 1.73 x 10 -15 s, whereas in [35] /I is (1.81 ± 0.06) x 10 -15 s (290 K).…”

EPR Linewidth Studies of Gd3 +‐Doped LaxNd1−xF3 Single Crystals

“…Thus we can write ABpp N l l y -l/x1. In the temperature range from 77 to 295 K, z1 = const because AB,, = const and g = const (g = 1.991 k 0.001 at 77K [16], g = 1.991 0.002 [8], and g = 1.9934 f 0.0015 [16] at room temperature. Assuming that g does not depend on the temperature above 295 K either and considering that AB,,, N T -" , we can write z1 -T" with n = -1/2 for LaF, (x = 1).…”

“…The investigation of the temperature dependence of the EPR linewidth can inform about the character of the interactions of the Gd3+ impurity ions with the Nd3+ host ions. In our previous paper [8] we have observed a temperature dependence of the EPR linewidths of Gd3+ ions (0.1 mol%) in NdF, single crystals and the effect of the spin-lattice relaxation narrowing proposed by Mitsuma [9] and discussed in the frame of the Kubo-Tomita [lo] theory.…”

EPR of Gd3+-Doped La0.9Nd0.1F3Crystal: Spin-Phonon Interactions and Spin-Lattice Relaxations

“…The EPR linewidths were measured in Gd3+-doped LaNdi_xF3 (0 < x < 1) single crystals in the temperature range from 77 to 510 K [7,8], whereas the magnetic susceptibility in the temperature range 1.5-300 K [9]. A temperature EPR (X-band) study of Gd 3 +-doped (0.1 mol%) La0 , 9 Nd0,iF3 single crystal has been carried out presently in order to *e-mail: mlpar©tytan.umcs.lublin.pl (367) investigate structural and crystal field effects, spin-phonon interactions, and dipolar interactions between Gd 3 + and Nd3+ ions.…”