Left: scheme of the Peltier calorimeter: (a) miniaturized Peltier cells working as heat flux sensors, (b) brass cylinder acting as thermal reservoir, (c) platinum resistance thermometer, (d) power Peltier cells, (e) brass blocks with water circulation system, and (f) thermally insulating layer. Right: the calorimetric cell (b).
Equivalent thermal circuit of the differential Peltier calorimeter.
Main plot: specific heat of sapphire. Points (squares): measurement by the calorimeter. Full line: literature data after Ref. 14. Inset: calibration curve. Points (circles): sensitivity of the cells, from Eq. (16). Line: fitting function with .
Specific heat of . Main plot: lines, apparent specific heat measured from scans at different rates without kinetic corrections; points from Perkin Elmer step-scan. Inset: specific heat by taking into account the kinetic corrections for the measuring cells [Eq. (11)].
Specific heat of as a function of the temperature for different applied magnetic field measured by the Peltier calorimeter.
Isothermal entropy change of as a function of the applied magnetic field measured by the Peltier calorimeter at selected temperatures : with dashed lines below and with full lines above . At is shown uncorrected curve (dotted line) and the corrected one (full line).
Specific heat of from heating and cooling temperature scans at 0.0 and 1.6 T applied magnetic field. Inset: detail around the Curie point of the ferromagnetic austenite.
Entropy change for different applied magnetic fields. Lines: from the differences of the entropy curves (shown in the inset). Points: isothermal measurements.
Entropy of from heating and cooling temperature scans at 0.0 and 1.6 T applied magnetic field, computed from the data of Fig. 7.
Entropy change of as a function of the applied magnetic field. Lines: from the differences of the entropy curves (Fig. 9). Points: isothermal measurements for the heating (h), circles, and cooling (c), squares, protocols. The inset shows a schematic phase diagram. The two dashed lines represent the thresholds for the transition from A to M and from M to A.
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