LOW-TEMPERATURE SPECIFIC-HEAT OF Y2CU2O5, TB2CU2O5, DY2CU2O5, HOCU2O5, ER2CU2O5, TM2CU2O5, YB2CU2O5, LU2CUO5 COMPOUNDS

Specific heat of rare earth cuprates R2Cu2O5 (R = Y, Tb-Lu) was measured in the temperature range 2.0 to 30 K. Specific heat anomalies corresponding to antiferromagnetic ordering of Cu2+ ions have been found. The Neel temperatures vary from T(N) = 10 K (R = Dy) to T(N) = 25 K (R = Er). For Yb2Cu2O5 and Dy2Cu2O5 compounds additional sharp peaks are observed at temperatures T = 9.5 K (R = Dy) and T = 6.8 K (R = Yb). These peaks may be associated with a spin-reorientation transition.