Synthesis and Characterization of the Phosphates Na1+xMg1+xCr2-x(PO4)3 (x = 0; 0.2) and NaZnCr2(PO4)3 with the α-CrPO4 Structure.

Single crystals of Na1.2Mg1.2Cr1.8(PO4)3 are prepared by drying (353 K, 24 h) a 6N HNO3 solution of Na2CO3, Mg(NO3)2, Cr(NO3)3, (NH4)H2PO4, and MoO3 followed by a complex heating schedule (the formed Na2Mo2O7 is used as a flux in 3-fold molar excess; Pt crucible, 473-873 K, 24 h/stage; 1523 K, 1 h).