Electron spin-lattice relaxation in a true amorphous material : V4+ in V 2O5

Abstract

The electron spin-lattice relaxation time T1 of V 4+ in amorphous V2O5 has been measured in the X-band between 1.4 K and 100 K : [FORMULA]. We explain this behaviour using a process requiring one two-level system (T.L.S.) modulating the crystal field, and one phonon. The characteristic temperature 56 K must be associated not with the maximum energy of the T.L.S. but with the cut-off in the distribution of the asymmetry parameter Δ. Spin-lattice relaxation is thus able to give informations about the asymmetry

Electron Spin Relaxation in Pseudo-Jahn–Teller Low-Symmetry Cu(II) Complexes in Diaqua(L-Aspartate)Zn(II)·H2O Crystals

“…The first term describes relaxation of a spin coupled to the nearby TLS with the integration over the TLS energy distribution from (14,(33)(34)(35). The second term describes the cross-relaxation between single ions and exchange coupled pairs (14, 36) (see A loc in Eq.…”

Some peculiarities of spin-lattice relaxation of impurity rare-earth ions in crystals caused by the structure defects

“…This concept was used for interpretation of measuring SLR in amorphous silicon a-Si [7] and for a V4 + centre in amorphous V205 [8], and observed nonlinear temperature dependences of the relaxation rate were described on this basis. Perhaps the similar ideas may be useful for the explanation of SLR "anomalies", observed in the crystals [3].…”

Tunnelling molecular motion in glassy glycerol at very low temperatures as studied by1H SQUID nuclear magnetic resonance

“…Several kinds of inorganic glass have been studied at low temperatures by nuclear magnetic resonance (NMR): temperature dependence of the nuclear spin-lattice relaxation rate was measured for each nucleus in glassy As 2 S 3 [10], glassy B 2 O 3 and (Na 2 ) 0.3 (SiO 2 ) 0.7 [11], glassy Na 2 B 4 F 7 and selenium [12]. Pulsed electron spin resonance was also applied to examine local amorphous structure in glassy V 2 O 5 by probing V 4+ [13] and the nature of paramagnetic centres produced by irradiation of amorphous K, Li and Na β-alumina [14]. Low-temperature properties of sodium β-alumina and fluorozirconate glasses were extensively studied by NMR [15][16][17][18][19][20][21], and the nuclear spin-lattice relaxation rate was found to show a simple power-law dependence on temperature, suggesting the presence of LFE [15,[18][19][20][21].…”