Magnetic phase transitions of Pr0.65Ca0.21Sr0.14MnO3 and Pr0.65Ba0.35MnO3 single crystals

The magnetic phase transitions in single crystals Pr0.65Ca0.21 Sr0.14MnO3 a nd Pr0.65Ba0.35MnO3 were studied using the magnetic moment measurement. The magnetization curves and temperature dependences of the magnetization at T > Tc were compared with those following from the phenomenological theory t aking into account the phase separation below Tc. This procedure verified t hat the ferromagnetic phase in both crystals undergoes the first-order tran sition to the paramagnetic state, which is in agreement with the NMR result s. Information on the temperature interval of the phase separation was also obtained. (C) 2001 Elsevier Science B.V. All rights reserved.