Теплофизические свойства мультиферроиков Bi-=SUB=-1-x-=/SUB=-Tm-=SUB=-x-=/SUB=-FeO-=SUB=-3-=/SUB=-

Investigations of the heat capacity, thermal diffusivity, and thermal conductivity of multiferroics Bi1-xTmxFeO3 (x = 0, 0.05, 0.10, 0.20) have been carried out in the high temperature range of 300-1200 K. and thermal conductivity in the region of phase transitions. The temperature dependences of the specific heat for compositions with x = 0.10 and 0.20 exhibit an additional anomaly characteristic of the phase transition at T = 580 K. The dominant mechanisms of phonon heat transfer in the region of ferroelectric and antiferromagnetic phase transitions are considered. The temperature dependence of the average phonon mean free path is determined.

Neutron Diffraction Study on the Magnetic Structure of 153EuMnO3-δ: One Way to Assess the Magnetic Structure of EuMnO3-δ

Owing to the strong neutron absorption of 151Eu, 151Eu free 153EuMnO3-δ has been synthesized to collect the neutron diffraction data for analyzing the magnetic structure of EuMnO3-δ. The obtained neutron diffraction data of 153EuMnO3-δ indicates that the magnetic diffraction peaks corresponding to cAAFM (canted A-type antiferromagnetic) phase can be observed, but the magnetic diffraction peaks corresponding to expected ICAFM (incommensurate antiferromagnetic) phase may be too weak to be observed.

Nonadiabatic Atomic-Like State Stabilizing Antiferromagnetism and Mott Insulation in MnO

This paper reports evidence that the antiferromagnetic and insulating ground state of MnO is caused by a nonadiabatic atomic-like motion, as is evidently the case in NiO. In addition, it is shown that experimental findings on the displacements of the Mn and O atoms in the antiferromagnetic phase of MnO corroborate the presented suggestion that the rhombohedral-like distortion in antiferromagnetic MnO, as well as in antiferromagnetic NiO is an inner distortion of the monoclinic base-centered Bravais lattice of the antiferromagnetic phases.