TY  - JOUR
AU  - Fu, Zhendong
AU  - Xiao, Yinguo
AU  - Su, Yixi
AU  - Zheng, Yanzhen
AU  - Kögerler, Paul
AU  - Brückel, Thomas
TI  - Low-lying magnetic excitations and magnetocaloric effect of molecular magnet K $_{6}$ [V $_{15}$ As $_{6}$ O $_{42}$ (H $_{2}$ O)] · 8H $_{2}$ O
JO  - epl
VL  - 112
IS  - 2
SN  - 0295-5075
CY  - Les-Ulis
PB  - EDP Science65224
M1  - FZJ-2015-07122
SP  - 27003
PY  - 2015
AB  - Low-temperature heat capacity measurements were performed on the molecular nanomagnet $\text{K}_{6}[\text{V}_{15}\text{As}_{6}\text{O}_{42}(\text{H}_{2}\text{O})] \cdot8\text{H}_{2}{\text{O}}$ (V15). The low-lying magnetic excitations are clearly evidenced by the Schottky anomalies in the specific-heat data. The energy levels determined from the low-temperature observables agree well with the three-spin model for V15. The magnetocaloric effect of V15 is examined. The maximum entropy change of $5.31\ \text{Jkg}^{-1}\text{K}^{-1}$ is found for a field change of $\Delta H =(8-0.5)\ \text{T}$ at ${\sim}1.5\ \text{K}$ . In spite of the low ground-state spin of V15, a drastic entropy change of $4.12\ \text{Jkg}^{-1}\text{K}^{-1}$ is observed for a field change of $\Delta H = (8-0.05)\ \text{T}$ at 0.4 K, which is comparable to the entropy change of some high-spin sub-kelvin magnetic coolers at such low temperatures. Anisotropy and consequent zero-field splitting result in this characteristic of V15 and may open new possibilities in the design of ultra-low-temperature molecular coolers.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000365323000023
DO  - DOI:10.1209/0295-5075/112/27003
UR  - https://juser.fz-juelich.de/record/278947
ER  -