Low temperature specific heat of R2Cu2O5 compounds (R=Y, Tb, Dy, Ho, Er, Tm, Yb, Lu)

Specific heat of cuprates of rare earths R2Cu2O5 (R=Y, Tb, Dy, Ho, Er, Tm, Yb, Lu) is measured for the first time in the temperature interval from 2.0 to 30 K. Anomalies of specific heat corresponding to phase transformations of the second type during antiferromagnetic ordering of Cu2+ ions are found. The Neel temperature, TN, for different R is within the limits of 10 K (R=Dy) - 25 K (R=Er). Additional sharp peaks in specific heat at T=9.5 K (R=Dy) and 6.8 K (R=Yb), connected probably with spin-reoriented transformations, are observed in Yb2Cu2O5 compounds besides peaks corresponding to magnetic ordering of Cu2+. Holmium, thulium, ytterbium, terbium cuprates have the Schottky anomaly caused rare earth ions energy levels splitting with crystal field