SQUID STUDIES OF PHOTOINDUCED MAGNETIZATION IN A GAMMA-FE2O3-ZN SINGLE-CRYSTAL

A photoinduced change (Delta m(l)) in the magnetization in a ferromagn etic single crystal gamma-Fe2O3 doped with zinc ions was discovered wi th a SQUID magnetometer. The effect is observed at temperatures T less than or equal to 60 K. Analysis of the characteristic features of the temperature dependences of Delta m(l) showed that the detected change s caused by the redistribution of the populations of the sublevels of the ground state multiplet of the Fe2+ ions in an optical pumping cycl e which leads to efficient cooling of the spin subsystem of the photoc enters. (C) 1995 American Institute of Physics.