A high-sensitivity differential scanning calorimeter with magnetic field for magnetostructural transitions

Abstract

We have developed a differential scanning calorimeter capable of working under applied magnetic fields of up to 5 T. The calorimeter is highly sensitive and operates over the temperature range 10-300 K. It is shown that, after a proper calibration, the system enables determination of the latent heat and entropy changes in first-order solid-solid phase transitions. The system is particularly useful for investigating materials that exhibit the giant magnetocaloric effect arising from a magnetostructural phase transition. Data for Gd 5 (Si 0.1 Ge 0.9 ) 4 are presented.

Magnetic superelasticity and inverse magnetocaloric effect in Ni-Mn-In

“…Magnetization measurements were carried out using a superconducting quantum interference device magnetometer, and calorimetric measurements in magnetic field were performed using a high-sensitivity differential scanning calorimeter. 16 Neutron diffraction in magnetic fields up to 5 T was performed on the D2B powder diffractometer at ILL, Grenoble. The strain measurements were made using conventional strain-gauge technique in magnetic fields up to 5 T.…”

Evaluation of the reliability of the measurement of key magnetocaloric properties: A round robin study of La(Fe,Si,Mn)Hδ conducted by the SSEEC consortium of European laboratories

“…However, the measure of specific heat under magnetic field can be more critical because relatively high magnetic field can be produced only over restricted volumes. The investigation of magnetocaloric effect has triggered the development of laboratory instrumentation for this purpose based on different calorimetric methods, for example: semiadiabatic heat pulse techniques (Pecharsky et al 1997 b ); relaxation calorimetry (Bachmann et al 1972) (adopted in the Quantum Design PPMS); and heat flux differential scanning calorimetry (DSC) (Jeppesen et al 2008;Marcos et al 2003;Plackowski et al 2002). In the case of a material showing a first order magnetic transition, it is interesting to separate the heat capacity and the latent heat contributions.…”

“…The temperature scanning techniques presented by Bachmann et al (1972), Plackowski et al (2002) and Marcos et al (2003) are based on the use of miniaturized thermoelectric modules (Peltier cells) as sensitive heat flux, q, sensors. In a temperature scan at rate T  , the specific heat can be determined by…”

Giant heat dissipation at the low-temperature reversible-irreversible transition inGd5Ge4

“…M͑T͒ curve on heating at 5 kOe after ZFC from 300 K showed a cuspid between 12 and 27 K, and the expected AFM-to-paramagnetic transition at Ӎ130 K, in agreement with previously reported results. 15,17 A second ZFC curve, recorded on heating at 5 kOe after applying a field of 50 kOe during a few seconds at 4 K, shows a strong decrease at ϳ25 K and matches the first ZFC curve above ϳ30 K. Isothermal magnetization curves were measured while increasing and decreasing the field after ZFC from above 130 K, at temperatures T = 4, 6,8,10,12,14,16,18,20,25,30,35,40, and 45 K. From 4 to 20 K, the magnetization curves while increasing the field showed the expected irreversible transition between AFM and FM phases, 15,17 the sample remaining in the FM phase after the field was further reduced down to zero. The presence of a 22% FM component in the virgin sample 16,22 was estimated from the saturation in the magnetization curve at 4 K, observed before the irreversible transition takes place.…”

“…22 The heat dissipated in a magnetization hysteresis loop Q M was calculated as the area comprised inside the loop. Calorimetric data were measured using a differential scanning calorimeter ͑DSC͒ operating under a magnetic field H. 25 Measurements were carried out by recording heat flow while H was swept at 10 kOe/ min at a constant temperature, which enables to obtain the heat released or absorbed by the sample as the integral of the calorimetric peak. 26 Calorimetric curves shown in Fig.…”