Eur. Phys. J. B 26, 135-140 (2002)
https://doi.org/10.1140/epjb/e20020074

Magnetic contributions to the low-temperature specific heat of the Pr_0.8Ca_0.2MnO₃

Laboratoire CRISMAT (Unité Mixte de Recherches 6508) , Institut des Sciences de la Matière et du Rayonnement – Université de Caen, 6 boulevard du Maréchal Juin, 14050 Caen Cedex, France

Corresponding author: ^a alexandre.wahl@ismra.fr

Received: 21 May 2001
Revised: 14 December 2001
Published online: 15 March 2002

Abstract

The Pr_1-xCa_xMnO₃ system exhibits a ferromagnetic insulating state for the composition range . A metallic ferromagnetic state is never realized because of the low hole concentration and the very small averaged A-site cation radius. In the present study, the nature of the magnetic excitations at low temperature has been investigated by specific heat measurements on a Pr_0.8Ca_0.2MnO₃ single crystal. The decrease of the specific heat under magnetic field is qualitatively consistent with a suppression of ferromagnetic spin waves in a magnetic field. However, at low temperature, the qualitative agreement with the ferromagnetic spin waves picture is poor. It appears that the large reduction of the specific heat due to the spin waves is compensated by a Schottky-like contribution possibly arising from a Zeeman splitting of the ground state multiplet of the Pr³⁺ ions.