KEr(MoO4)2: A quasi-one-dimensional

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

“…The authors suggest that in the pure dipolar approach the compound can be treated as a quasi-ID magnetic system. The suggestions were later confirmed by ΚΕr(ΜοO4)2 specific heat studies [4]. The analysis of the data in zero magnetic field performed within nearest-neighbour exchange-coupling model has revealed that in the temperature range from 0.5 K to 5 K the magnetic system can be approximated by S = 3/2 Blume-Capel model on rectangular lattice with intrachain interaction J'1/kΒ = 0.38 K, interchain interaction J'2/J'1 -0.2 and single-ion anisotropy D/kB = 10 K. It was found that for the given set of parameters at temperatures lower than 2 K this model converges to S = 1/2 Ising model on the rectangular lattice with effective intrachain interaction J1/k = 0.85 K and effective interchain interaction J2/J1 -0.2.…”

“…(The J' and J are related by the transformation J' = (4/9)J due to different spin magnitudes of the used models.) Preliminary studies of the contribution of spin cluster excitations to the specific heat in nonzero magnetic field applied along the c-axis was reported in [4]. The analysis of the data performed within the same models revealed that the data in B ψ 0 require renormalization of the J'1, J ' 2 p a r a m e t e r s .…”

“…The magnetic field dependence of ΚΕr(ΜοO4)2 specific heat was experimentally studied by using a standard quasi-adiabatic calorimetry [4] at the constant temperature T = 4.27 K in magnetic fields up to 1 T. Since the studied compound can be treated as a magnetic insulator, the lattice contribution was separated using the method described elsewhere [4]. The resultant magnetic specific heat is shown in Fig.…”

“…The data are compared with the behaviour of S = 1/2 Ising model on the square lattice with íntralayer exchange interaction J/kB = 0.56 K in B || z. The theoretical prediction was calculated by the Monte Carlo method with parameters described in detail elsewhere [4]. Despite of the preliminary character of the data, it is clear that also in this case a different value of J should be used to improve the agreement with the experiment.…”

Magnetic-Field Induced Slow Relaxation in the Ising-Like Quasi-One-Dimensional Ferromagnet KEr(MoO_4)_2

“…The ground state of a free Er 3+ is 4 I 15/2 multiplet, which is split into 8 Kramers doublets with the energies E 1 = 22, (893) [4]. Interplay of crystal field and dipolar interactions results in the formation of a two-dimensional array of the Ising ferromagnetic chains below 2 K. The antiferromagnetic interchain coupling leads to the phase transition to magnetic long-range order at 0.9 K [8].…”