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Title: Temperature dependent low-field measurements of the magnetocaloric ΔT with sub-mK resolution in small volume and thin film samples

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4906426· OSTI ID:22415145
;  [1]; ;  [2];  [3];  [3]
  1. Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany)
  2. Institut für Materialwissenschaft, TU Darmstadt, 64287 Darmstadt (Germany)
  3. Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany)

We present temperature dependent ΔT measurements of the magnetocaloric effect in a thin film sample of Gd, employing magnetomodulation and detection of thermal radiation. A bulk sample of the metamagnetic material LaFe{sub 11.05}Co{sub 0.91}Si{sub 1.04} shows a strong broadening of the ΔT peak for increasing field amplitudes between 4 and 45 mT. Bulk Gd in comparison shows only a weak broadening. All investigated samples exhibit a clear quadratic dependence of ΔT on the external field H{sub ext} at the ΔT peak maximum, contrary to earlier predictions. An analytic expression is derived that interpolates between the H{sub ext}{sup 2}-behavior at low and the well-known H{sub ext}{sup 2/3}-behavior at high fields.

OSTI ID:
22415145
Journal Information:
Applied Physics Letters, Vol. 106, Issue 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English