Peculiarities of Magnetic Phase Separation in Anion-Deficient La0.70Sr0.30MnO2.85 Manganite

The temperature and field dependences of the specific magnetic moment of the anion-deficient La0.70Sr0.30MnO2.85 manganite have been measured. It is established, that the magnetic state of the sample studied is a cluster spin glass and it is the result of frustration of exchange Mn3+-O-Mn3+ interactions due to the redistribution of oxygen vacancies. The increase of the magnetic field leads to an increase in the degree of polarization of local spins of manganese. It is established using the magnetic criterion that a phase transition into the paramagnetic state for the anion-deficient La0.70Sr0.30MnO2.85 manganite is a thermodynamic second order phase transition. The causes and mechanism of the magnetic phase separation are discussed.