Analysis of the magnetic properties of (La sub(1 - x )Sr sub(x)) sub(0.93)MnO sub(3) manganites at high temperatures

For the first time, the Faraday method is used to measure the temperature dependence of paramagnetic susceptibility j(T) of (La sub(1 - x)Sr sub( x)) sub(0.93)MnO sub(3) (x = 0.2, 0.25, or 0.3) manganites in the temperature interval 60-850C. It is demonstrated that the dependences have two kinks and three linear sections. The kink of curve j super(-1)(T) is related to polymorphic transformations (Q' 1 Q* and Q* 1 R) that take place in the crystal lattices of the samples. The main magnetic characteristics of the samples are determined with the least-squares processing of curve j super(-1). Is is demonstrated that dependence j super(-1)(T) obeys the Curie-Weiss law. The energy state of the magnetoactive manganese atom in the Q'-and Q*-phase samples is close to the energy state of a free Mn super(2+) ion. In the R phase, this state is close to the state of a free Mn super(3+) ion.