CRYSTAL-GROWTH, IR AND RAMAN-SPECTRA, THERMAL-DECOMPOSITION AND MAGNETIC-PROPERTIES OF KPR(CRO4)2, KND(CRO4)2, KSM(CRO4)2

The double chromates of formula KLn(CrO//4)//2 (Ln EQUVLNT Pr, Nd, Sm) were prepared as single crystals by hydrothermal synthesis from the oxides Pr//6O//1//1, Nd//2O//3 and Sm//2O//3 respectively and K//2Cr//2O//7 solution at 150 degree C in sealed tubes. These compounds were also obtained as microcrystalline powders in the above-mentioned hydrothermal process and by solid reaction of the oxides Pr//6O//1//1, Nd//2O//3 and Sm//2O//3 with KNO//3 at 450 degree C. These materials are isostructural with KLa(CrO//4)//2 which crystallizes in the monoclinic system with space group P2//1/c and Z equals 4. Crystallographic data, IR and Raman spectra, thermal decomposition and magnetic properties of these compounds were studied.