Multiple slow relaxation of magnetization in Dy³⁺ confined in the crystal matrix of rare-earth-calcium silicates with the apatite structure

Abstract

Dy3+ reveals slow relaxation of magnetization in both Dy-diluted and Dy-rich silicates with enhanced relaxation times in the latter.

Dysprosium magnesium silicate apatite featuring field and temperature stable slow magnetization relaxation

“…6 as functions of temperature. The relaxation behavior resembles that in the Dy-Ca silicate apatite 18 which was analyzed in a narrower eld-temperature range though. For the sake of comparison the respective data for the latter compound are also shown in Fig.…”

“…In ref. 18 we offered a phenomenological explanation for observing several s values from the single paramagnetic center. Two requirements have to be fullled.…”

“…The Dy-Mg compound shows slightly larger s values of SR in comparison with the Dy-Ca compound. 18 Such behavior may be expected since the crystal lattice is compressed by the Mg for Ca substitution. However the changes of the SR parameters are surprisingly small.…”

“…Similar deviations in M(H) we have observed for the Dy-Ca silicate apatite and we have assumed as possible reasons inter-ion dipole or/and exchange interactions. 18 Here we performed a tentative analysis of the dipolar interactions restricting them to the (Dy2) 6 octahedron. Dipolar energy for every pair of Dy 3+ ions was calculated using formula (3).…”

“…Symbolsdata for the Dy-Mg silicate apatite; linesdata for the sister compound, Dy-Ca silicate apatite. 18 Error bars correspond to two standard deviation values. They are shown if exceeding the symbol size.…”