Ferromagnetic–antiferromagnetic state in manganites

Magnetic and electrical properties of La1−xSrxMnO3 (x=0.1, 0.15 and 0.3) single-crystals, Eu0.7A0.3MnO3 (A=Ca, Sr) ceramics, and La0.84Sr0.16MnO3 and La0.1Pr0.6Ca0.3MnO3 epitaxial thin films are investigated. Curves of T-dependence of the electrical resistivity and the magnetoresistance show the maxima near Curie point and magnetoresistance is colossal in maximum. Distinction between the magnetizations and the remanences of zero-field-cooled and field-cooled sample and displacement of hysteresis loop of field-cooled sample are found in La0.9Sr0.1MnO3 single-crystals, Eu0.7A0.3MnO3 (A=Ca, Sr) ceramics, and La0.84Sr0.16MnO3 and La0.1Pr0.6Ca0.3MnO3 epitaxial thin films. This displacement denotes that magnetic two-phase ferro–antiferromagnetic state is inherent in them. From this displacement the exchange integral described the Mn–O–Mn connection across droplet/host interface, is calculated. The presence of ferromagnetic (F) and antiferromagnetic (AF) states in Eu0.7A0.3MnO3 (A=Ca, Sr) is confirmed by next facts: magnetization isotherms at T