title: Modification of crystal anisotropy and enhancement of magnetic moment of Co-doped SnO2 thin films annealed under magnetic field.
abstract: Co-doped SnO2 thin films were grown by sputtering technique on SiO2/Si(001) substrates at room temperature, and then, thermal treatments with and without an applied magnetic field (HTT) were performed in vacuum at 600°C for 20 min. HTT was applied parallel and perpendicular to the substrate surface. Magnetic M(H) measurements reveal the coexistence of a strong antiferromagnetic (AFM) signal and a ferromagnetic (FM) component. The AFM component has a Néel temperature higher than room temperature, the spin axis lies parallel to the substrate surface, and the highest magnetic moment m =7 μB/Co at. is obtained when HTT is applied parallel to the substrate surface. Our results show an enhancement of FM moment per Co(+2) from 0.06 to 0.42 μB/Co at. for the sample on which HTT was applied perpendicular to the surface. The FM order is attributed to the coupling of Co(+2) ions through electrons trapped at the site of oxygen vacancies, as described by the bound magnetic polaron model. Our results suggest that FM order is aligned along [101] direction of Co-doped SnO2 nanocrystals, which is proposed to be the easy magnetization axis.
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Sagrario M
authors.initials: SM
authors.lastname: Loya-Mancilla
authors.affiliation: Physical and Materials Chemistry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Poddar
authors.affiliation: Physical and Materials Chemistry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Raja
authors.initials: R
authors.lastname: Das
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Hilda E Esparza
authors.initials: HE
authors.lastname: Ponce
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Ivan L
authors.initials: IL
authors.lastname: Templeton-Olivares
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Oscar O
authors.initials: OO
authors.lastname: Solis-Canto
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Ornelas-Gutierrez
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Espinosa-Magaña
authors.affiliation: Centro de Investigación en Materiales Avanzados, S.C., Cimav, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109 Chihuahua, Chihuahua, Mexico.
authors.forename: Sion F
authors.initials: SF
authors.lastname: Olive-Méndez
keywords: Antiferromagnetism; Crystal anisotropy; Diluted magnetic oxide; Ferromagnetism; Magnetic anisotropy; Magnetic moment; Spin axis; Thin film