Specific heat, magnetization and DC susceptibility of the single crystal CsNd(MoO_{4})_{2},a layered rare-earth dimolybdate, have been investigated nominally, in the temperature range from 100 mK to 300 K in the magnetic field up to 5 T, applied along the a axis. The analysis of the experimental data revealed the absence of a phase transition to the magnetic ordered state down to 100 mK. The application of a standard two-level model yielded an excellent agreement with the specific heat data above 2 K in nonzero magnetic field indicating a weakness of magnetic correlations and a predominant occupation of the ground-energy doublet. The latter indicates a large energy separation between the ground and first excited doublet. These measurements suggest that CsNd(MoO_{4})_{2} can represent a good realization of a single-ion magnet.
The thermal conductivity of CsGd(MoO_4)_2 has been studied in the temperature range from 2 to 50 K in zero magnetic field. The analysis of the data performed within the Debye model with the relaxation-time approximation revealed the presence of the scattering of phonons by critical fluctuations. The behaviour of phonon mean free path at the lowest temperatures is discussed.
The thermal conductivity of the quasi-one-dimensional S = 5/2 Heisenberg antiferromagnet CsMnCl_3·2H_2O with the intrachain interaction J/k_{B} = 3 K was experimentally studied at temperatures from 2 to 25 K. The data analysis performed within the Debye model with the relaxation-time approximation unambiguously indicates the presence of the scattering of phonons on magnetic subsystem.
Structural analysis of [Ni(en)(H_2O)_4][SO_4]·2H_2O was performed and it suggests that the crystal field should play a dominant role in the magnetic properties of the system. This conjecture coincides well with the specific heat and susceptibility behaviour. The analysis confirmed that the compound can be treated as a spin 1 single molecule magnet with nonmagnetic ground state introduced by easy-plane single-ion anisotropy D/k_B≈11 K and neglecting in-plane anisotropy E/D <0.1.
The heat transport in a single-crystal of CsNiF_3 has been performed in the temperature range from 2 K to 7 K in a zero magnetic field, B = 0, as well as in sufficiently large magnetic fields, B = 6 T and 9 T, inducing the ferromagnetic ground state along the hard c-axis. CsNiF_3 represents an S = 1 quasi-one-dimensional XY ferromagnet with the intra-chain exchange coupling J/k_{B} ≈ 24 K, single-ion anisotropy D/k_{B} ≈ 8 K, and ordering temperature T_{N} = 2.7 K. Comparison of the phonon and magnon velocities suggests that phonons are the main heat carriers in this magnetic insulator. The thermal conductivity in B = 0 was analysed in the frame of a standard Debye model. The temperature dependence of the effective phonon mean free path was calculated from the experimental data, and the enhancement of the phonon mean free path in B ≠ 0 was obtained, indicating that magnons act as scattering centers for phonons.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.