Magnetic heat capacity in lanthanum manganite single crystals
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States)
- Joint Research Center for Atom Technology, 1-1-4 Higashi, Tsukuba 305-0046, (Japan)
The heat capacity of single crystal La{sub 0.7}D{sub 0.3}MnO{sub 3}, where D=Ca, Sr, has been measured through the Curie point in fields up to 70 kOe. The magnetic contribution of the Ca sample exhibits a sharp heat capacity peak at T{sub C}(approx =)218 K in zero field. The peak broadens and decreases in height with increasing field but, unlike an ordinary ferromagnet, the peak shifts substantially in temperature. As a consequence, the heat capacity data cannot be collapsed into a single scaling function. These features indicate that the transition is not an ordinary second-order ferromagnetic transition. Preliminary heat capacity data from the Sr-doped single crystal, with T{sub C}{approx_equal}360 K, do not exhibit the same shift in peak position with applied field. We attribute the difference in behavior between Ca- and Sr-doped samples to a change in the nature of the phase transition as T{sub C} lowers. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20216251
- Journal Information:
- Journal of Applied Physics, Vol. 87, Issue 9; Other Information: PBD: 1 May 2000; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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