0000000000699634
AUTHOR
Andrzej W. Pacyna
Anomalies in low-temperature lattice parameters of ErFeO3 and ErAlO3 single crystals: correlation with magnetic properties
Abstract The paper presents the results of an experimental study of thermal expansion of isostructural orthorhombic ErFeO3 and ErAlO3 single crystals. Changes of lattice parameters have been investigated by X-ray measurements in the 10–300 K temperature range. Above ∼150 K, experimental results correspond well to the phonon mechanism. At low temperatures distinct anisotropic anomalies were observed in both compounds; and a correlation with the magnetic properties of the relevant ions is noted.
Spontaneous magnetostriction and thermal expansibility of TmFeO3 and LuFeO3 rare earth orthoferrites
Abstract At low temperatures the TmFeO3 orthoferrite shows a strong spontaneous magnetostriction generated by rare earth Tm atoms. This effect essentially depends on the temperature and orientation of the weak ferromagnetism vector of the Fe sublattice and reaches largest values for the directions [1 0 0] and [0 0 1]. The spin reorientation process in TmFeO3 marks itself mainly in the change of the signs of the linear thermal expansion coefficients in the directions mentioned above. Some additional singularities of thermal dependencies of expansion coefficients are observed below 20 K, which may be due to a magnetic compensation effect in the investigated orthoferrite.