DC magnetic susceptibility and neutron powder diffraction analysis of the perovskite-type compounds LaYbO₃and LaHoO₃

Abstract

Magnetization measurements and neutron powder diffraction analyses followed by Rietveld refinement have been carried out in order to investigate the magnetic structures of LaYbO3 and LaHoO3. Both compounds exhibit a negative thermal expansion along the a and b axes. In LaYbO3 Yb(3+) spins order at 2.4 K according to a FyGz-type structure, belonging to the Pn'ma' magnetic space group. Conversely, LaHoO3 is paramagnetic down to 1.5 K.

Formation enthalpies of LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) interlanthanide perovskites

“…1), which is consistent with Bharathy's crystallographic data on single crystals of interlanthanides [6]. The unit cell parameters obtained are also consistent with those reported by Martinelli et al [12]. The grain size of all samples is in the micron range as they were calcined at high temperature for a long time.…”

“…A comprehensive study of preparation and stability of interlanthanide perovskites was done by Berndt et al [2] and their unique magnetic properties were studied by Kentaro et al [7]. Recently, Artini et al presented a comprehensive study of the preparation and structural properties of interlanthanide perovskite compounds [4,5,12]. Bharathy et al [6] reported the growth of single crystals of the interlanthanides series LaLn'O 3 (Ln'=Y, Ho-Lu) using molten hydroxide fluxes.…”

New insights into the magnetic properties of LaErO3, (La0.5Er0.5)2O3and (La0.5Dy0.5)2O3oxides

“…In LaErO 3 magnetic moments approximately lie in a plane formed by the two axial O(1) atoms and two equatorial O(2) ones, pointing towards the centre of one of the octahedron edges. This arrangement is somehow similar to that detected in LaYbO 3 , despite its different magnetic structure (F y G z -type ordering) [12]: here the ordered magnetic moments lie in the plane formed by the four O(2) atoms, but also in this case the moments point towards the centre of one of the octahedron edges (figure 3).…”

“…In this structure the smaller Er 3+ ion is in 6-fold coordination and located at the centre of an octahedron, whereas the larger La 3+ ion displays a 12-fold coordination. The octahedral tilting in LaErO 3 corresponds to the a + b − b − system (N. 10) proposed by Glazer for perovskite structures [24], as in LaYbO 3 and LaHoO 3 [12].…”

“…Recently our research group carried out an investigation on orthorhombic LaYbO 3 and LaHoO 3 based on neutron powder diffraction; as a result, it was found out that Yb 3+ magnetic moments order in LaYbO 3 at 2.4 K according to a F y G z -type structure, belonging to the Pn′ma′ magnetic space group, whereas LaHoO 3 is paramagnetic down to 1.5 K [12].…”