ИСТИНА

We have investigated the thermopower and magnetothrmopower of Sm0.55Sr0.45MnO3 single crystal in which CE-type antiferromagnetic (AF) phase is dominant. The temperature dependence of thermopower have the broad maximum in the Neel temperature whereas at this temperature the giant minimum take place on the magnetothremopower from temperature curve. Sharp decrease of thermopower under the action of magnetic field is connected to destruction of CE-type of AF phase. Electrical current flowed in sample at the thermopower measurements causes Peltier effect on boundary of CE-type AF cluster and a temperature overall deltaT arises on this cluster. Internal thermopower is caused by influence of deltaT and is equal to (alfa1 minus alfa)x deltaT, where alfa1 is thermopower of cluster. Sharp decrease of crystal's thermopower in Neel point shows big contribution in it from the AF CE-type clusters.