The unusual magnetism of nanoparticle LaCoO3. (8th May 2015)

• Record Type: Journal Article
• Authors: Durand, A M; Belanger, D P; Hamil, T J; Ye, F; Chi, S; Fernandez-Baca, J A; Booth, C H; Abdollahian, Y; Bhat, M
• Is Part Of: Journal of physics. Volume 27:Number 17(2015)
• Page Start: 376
• Publication Date: 2015-05-08
• Subjects: Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/17/176003
• Languages: English
• ISSNs: 0953-8984

Abstract

<abstract> <title>Abstract</title> <p>Bulk and nanoparticle powders of LaCoO₃ (LCO) were synthesized and their magnetic and structural properties were studied using SQUID magnetometry and neutron diffraction. The bulk and large nanoparticles exhibit weak ferromagnetism (FM) below <italic>T</italic> ≈ 85 K and a crossover from strong to weak antiferromagnetic (AFM) correlations near a transition expressed in the lattice parameters, <italic>T</italic>_o≈40 K. This crossover does not occur in the smallest nanoparticles; instead, the magnetic behavior is predominantly ferromagnetic. The amount of FM in the nanoparticles depends on the amount of Co₃O₄ impurity phase, which induces tensile strain on the LCO lattice. A core-interface model is introduced, with the core region exhibiting the AFM crossover and with FM in the interface region near surfaces and impurity phases.</p> </abstract>