The specific heat C(T) of the monoclinic RbDy(WO4)2 crystal has been studied at very low temperatures 0.2 ≤ T ≤ 1.9 K and in magnetic fields 0 ≤ H ≤ 0.38 T. The Neel temperature was shown to be equal to TN = 0.818 ± 0.005 K. The experimental value of the effective exchange parameter was obtained to be equal to J/k = -0.798 K. The C(T) dependence below Neel temperature (0.5 TN < T < 0.99TN) is well described by 2D Ising model, whereas in the temperature region close above TN (1.01TN < T < 2TN) it can be described by neither 2D, nor 3D Ising model. The experimental and theoretical H-TN diagrams for field H ∥ a are in a reasonable agreement for simple quadratic lattice.
|Number of pages||9|
|Journal||Journal of Low Temperature Physics|
|State||Published - 1 Jan 1998|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science (all)
- Condensed Matter Physics