Evidence of dipole spin glass in magnetically dilute dielectric CaF2:Er3+
Atsarkin V. A. , Demidov V. V., Khlebnikov S. Ya.
A formation of spin glass due to magnetic dipole interaction between impurity ions was observed for the first time in the investigation of magnetic susceptibility in CaF2 crystals with a 1 % impurity of Er3 + ions (effective spin S' — 1/2) at temperatures below 0.8 K.