Anomalous temperature behavior of resistance in C1-xCox thin films grown by pulsed laser deposition technique

Author(s)

Sergeenkov, S. ^{[1, 2]} ; Cordova, C. ^[2] ; Cichetto, Jr., L. ^{[3, 2, 4]} ; de Lima, O. F. ^[5] ; Longo, E. ^{[3, 4]} ; Araujo-Moreira, F. M. ^[2]

Affiliation

^[1] Univ Fed Paraiba, CCEN, Dept Phys, BR-58051970 Joao Pessoa, PB - Brazil

^[2] Univ Fed Sao Carlos, Dept Phys, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Chem, LIEC, BR-13565905 Sao Carlos, SP - Brazil

^[4] Univ Estadual Paulista, UNESP, Inst Chem, BR-14801907 Araraquara, SP - Brazil

^[5] Univ Estadual Campinas, Inst Phys Gleb Wataghin, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 667, p. 18-22, MAY 15 2016.
• Web of Science Citations: 2

Abstract

We study the transport properties of C1-xCox thin films (with x = 0.1, 0.15 and 0.2) grown on Si substrate by pulsed laser deposition technique. The results demonstrate some anomalous effects in the behavior of the measured resistance R(T,x). More specifically, for 0 < T< T{*} range (with T{*} similar or equal to 220 K) the resistance is shown to be well fitted by a small polaron hopping scenario with R-h(T,x) proportional to exp[{[}T-0(x)/T](0.5)] and a characteristic temperature T-0(x) similar or equal to T-0(0)(1 - x) (with T-0(0) = 120 K). While for higher temperatures T{*} <T < T-C(x), the resistance is found to be linearly dependent on spontaneous magnetization M(T,x), viz. R-M(T,x)proportional to M(T,x), following the pattern dictated by electron scattering on cobalt atoms formed robust ferromagnetic structure with the Curie temperature T-C(x) obeying a percolation like law T-C(x)similar or equal to T-C(x(m))(x/x(m))(0.15) with T-C(x(m)) = 295 K and the maximum zero-temperature magnetization reaching M(0, x(m))=0.5 mu(B) per Co atom for x(m) = 0.2. (c) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/01371-5 - Obtention of memories with LaNiO3 and LaNiO3/BaTiO3 using PLD
• Grantee: Leonélio Cichetto Junior
• Support type: Scholarships in Brazil - Post-Doctorate