Specific heat of some phosphate compounds

Abstract Specific heats C E p of some phosphates have been measured on powder samples, in the temperature range 100–373 K. Anomalous behaviour of C E p ( T ) has been observed for Co(H 2 PO 4 ) 2 s 2H 3 PO 4 and Mn(H 2 PO 4 ) 2 2H 3 PO 4 around 190 K. In triclinic Ba(H 2 PO 4 ) 2 a phase transition was found at about 147 K, i.e. at a somewhat higher temperature than according to previous dielectric measurements.