Evidence of a canted magnetic state in self-doped LaMnO3+δ (δ = 0.04): a magnetocaloric study

• Published in: Journal of physics. Condensed matter Vol. 24; no. 36
• Main Authors: Chandra, Sayan, Biswas, Anis, Datta, Subarna, Ghosh, Barnali, Siruguri, V, Raychaudhuri, A K, Phan, M H, Srikanth, H
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 12.09.2012; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetotransport phenomena, materials for magnetotransport; Manganites; Physics; Landau theory; Magnetocaloric effects; Neutron diffraction; Doping; Polycrystals; Magnetic structure; Ferromagnetic-paramagnetic transitions; Magnetic transitions; Manganites; Lanthanum Manganites
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/24/36/366004

We report a detailed investigation of the magnetocaloric properties of self-doped polycrystalline LaMnO3+δ with δ = 0.04. Due to the self-doping effect, the system exhibits a magnetic transition from a paramagnetic to ferromagnetic-like canted magnetic state (CMS) at ∼120 K, which is associated with an appreciably large magnetocaloric effect (MCE). The CMS is an inhomogeneous magnetic phase developing due to a steady growth of antiferromagnetic correlation in its predominant ferromagnetic state below ∼120 K. The stabilization of CMS in this material is concluded from a comprehensive analysis of magnetocaloric data using Landau theory, which is in excellent agreement with our neutron diffraction study. The magnetic entropy change versus temperature curves for different applied fields collapse into a single curve, revealing a universal behavior of MCE. Our studies suggest that investigation of MCE is an effective technique to acquire fundamental understanding about the basic magnetic structure of a system with complex competing interactions.