The magnetic phase transition in layered cesium rare earth metal dimolybdates

Abstract

2014 Des mesures de chaleur spécifique de CsGd (MoO4)2, CsDy (MoO4)2 et CsDy0,95Eu0,05 (MoO4)2 montrent des anomalies aigües à Tc = 0, 448 K, Tc =1, 288 K et Tc = 1, 227 K, respectivement. Les résultats sont comparés aux prédictions du modèle d'Ising à 2D et 3D. Abstract 2014 Heat capacity measurements on CsGd (MoO4)2, CsDy (MoO4)2 and CsDy0.95Eu0.05 (MoO4)2 show that sharp anomalies occur at Tc = 0.448 K, Tc = 1.288 K and Tc = 1.227 K, respectively. The heat capacity behaviour is compared with 2D and 3D Ising model.

KEr(MoO4)2and CsDy(MoO4)2- Low-Dimensional Ising Magnets

“…However, in comparison with ΚΕr(ΜoO 4 ) 2 , the strength of interchain interactions is much larger. This fact corresponds with previous specific heat studies in B = 0 indicating that the system can be described by S = 1/2 Ising model on the square lattice with J/kB = 0.56 K [7]. To estimate magnetic field dependence of CsDy(ΜοO4)2 specific heat, the results of [8] were used where the temperature dependence of specific heat in a constant magnetic field B c was studied.…”

The specific heat of - a quasi-one-dimensional Ising ferromagnet

“…for KEr(MoO 4 ) 2 (this work), CsDy(MoO 4 ) 2 and theoretical predictions for the S = 1/2 2D square (sq) and 3D simple cubic (sc) Ising lattices [8] Single-crystal samples were prepared by the flux method [16], with typical dimensions 15 × 10 × 1 mm 3 and weight of 1 g. The specific heat measurements were performed in two experimental devices. For temperatures above 2 K, standard adiabatic calorimetry was used in a 4 He cryostat equipped with a mechanical heat switch between the cold thermal reservoir and the sample cell.…”

“…In these ionic crystals the R 3+ ions occupy sites which are sufficiently far apart from one another that dipolar coupling represents the dominating interaction among magnetic moments [7]. The moments of the rare-earth ions in an AR(MO 4 ) 2 lattice are often very anisotropic, in some cases leading to good approximations of the Ising model [8].…”

“…At helium temperatures, Dy 3+ behaves as an Ising ion with an effective spin 1/2. Thermodynamic studies [11] showed that the magnetic heat capacity in the critical region corresponds to the behaviour of the two-dimensional Ising system. Theoretical calculations 0953-8984/98/051125+06$19.50 c 1998 IOP Publishing Ltd considering only dipolar interactions [12] revealed that the magnetic structure of the ground state consists of weakly coupled ferromagnetic chains of Dy 3+ ions parallel to the c-axis with magnetic moments oriented along the chains.…”

Effect of Layered Structure on the Lattice Heat Capacity of the Rare Earth Molybdates

“…Recently, the interest to study this group of material was enhanced by the observation of the phase transition into a complex noncolinear magnetically ordered state with strong anisotropic interaction, taking place at temperatures around 1 K or even lower [4].…”