Magnetic glass state and magnetoresistance in SrLaFeCoO6 double perovskite. (20th January 2017)

• Record Type: Journal Article
• Authors: Pradheesh, R; Nair, Harikrishnan S; Haripriya, G R; Senyshyn, Anatoliy; Chatterji, Tapan; Sankaranarayanan, V; Sethupathi, K
• Is Part Of: Journal of physics. Volume 29:Number 9(2017)
• Publication Date: 2017-01-20
• Subjects: magnetic glass -- magnetoresistance -- disordered double perovskite; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa5470
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Unusual features in magnetization resembling the kinetic arrest of a magnetic glass state are observed in the La-doped double perovskite, SrLaFeCoO6 . Neutron powder diffraction experiments confirm the presence of antisite disorder as well as a lack of long-range magnetic order down to 4 K in this double perovskite which displays spin glass-like features in dc and ac susceptibilities. Magnetic relaxation observed through cooling and heating under unequal fields (CHUF) point towards unusual domain dynamics which is supported by a broad memory effect . Among the two anomalies that are observed at T a 1 ≈ 75 K and at T a 2 ≈ 250 K in the magnetic measurements, the former is associated with a spin-freezing temperature below which the magnetic glass state is experimentally verified. The magnetometric experiments detailed in the paper bring out the non-equilibrium metastable magnetic states in this disordered magnetic system. The magnetic glass state described above manifests in the electrical resistivity ρ ( T ) through the formation of a 'hard gap' because of the spin-exchange energy following the formation of magnetic glass. It is observed that the combination of disorder and magnetic glass state leads to a large, negative magnetoresistance (MR) of ≈47 % at 5 K in 8 T.