The specific heat of potassium holmium double tungstate

Abstract

The results of measurements of thermal properties (specific heat) of potassium holmium double tungstate KHo(WO 4 ) 2 as a function of temperature (from 0.5 to 300 K) and magnetic field (up to 2 T) are presented. The total specific heat without the phonon and Schottky contributions is found to have the anomaly with maximum at T SPT $ 5 K. This anomaly is likely related with the structural phase transition (SPT) caused by the cooperative Jahn-Teller effect. The increase of specific heat at very low temperatures and its shift towards high temperatures with increasing magnetic field are observed. The origin of this behaviour can be connected with possible magnetic phase transition induced by magnetic field.

Magnetic phase transition in KGd(WO4)2 double tungstate

“…They were found to be equal to α ≈ 0 103 ± 0 018 (T < T N ) and α ∼ 0 116 ± 0 007 (T > T N ). Similar behaviour of the specific heat was observed for other double tungstates, for example: at 0.6 K for KDyW [14], at 0.82 K for RbDyW [8][9][10][11][12][13][14][15] and at 0.48 K for KErW [4]. The magnetic nature of the phase transition occurring at 0.42 K (for KGdW; this paper) will be verified by planned measurements of the magnetization at ultralow temperatures.…”

“…Many of them show complicated structural phase transitions (SPT), caused by the cooperative Jahn-Teller effect (CJTE), and magnetic phase transitions. The studies of these compounds are of scientific interest because of their magnetic behavior peculiarities at ultralow temperatures [7][8][9][10]. This short communication extends these studies by investigating the specific heat of potassium gadolinium double tungstate at ultra-low temperatures.…”

The magnetic properties of potassium holmium double tungstate

“…At ~20 T K, the lines, which describe temperature dependences of susceptibility along the a and c directions, change the angle of inclination. This may be connected with structural phase transition at T = 5.5 K [11].…”