ИСТИНА

In this work we have investigated impact of fluorine by hydroxide substitution on magnetic properties of cobalt and dysprosium containing apatites with single ion magnet properties. Hydroxides are the second surrounding of magnetic ions and also could affect on their properties. Dy containing calcium phosphates as well as cobalt containing barium, strontium and calcium phosphates were investigated. All the series keep their magnetic properties so magnetic centers in such compounds are quite stable. Dy containing samples show a small growth of Ueff with fluorine introduction. Ueff of cobalt containing samples stay nearly the same after fluorine insert but the observed paramagnetic centers concentration falls substantially due to competition with fluorides for positions inside the trigonal channels. This effect also causes the disappearance of single ion magnet properties in strontium and barium compounds with very high fluorine and the smallest cobalt concentrations.