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Thickness and Temperature Dependent Out‐of‐Plane Anisotropy of Amorphous CoSiB Thin Films
Author(s) -
Zhang Yu,
Wang SanSheng,
Li Fang,
Jiang Wen,
Zhang ZhuLi,
Chen ZiYu
Publication year - 2018
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201800041
Subject(s) - condensed matter physics , amorphous solid , materials science , anisotropy , magnetization , thin film , atmospheric temperature range , film plane , annealing (glass) , magnetic anisotropy , relaxation (psychology) , transition temperature , crystallography , composite material , chemistry , superconductivity , optics , magnetic field , nanotechnology , thermodynamics , physics , psychology , social psychology , quantum mechanics
Amorphous CoSiB thin films are prepared on Si (111) substrate at different temperatures. A thickness‐induced reversible spin reorientation transition (SRT) of the magnetic direction from in‐plane to out‐of‐plane is observed in the thick films due to the presence of out‐of‐plane anisotropy. Out‐of‐plane anisotropy is abnormally enhanced during the annealing process for films deposited at a low temperature, so the stress relaxation has no influence on out‐of‐plane anisotropy. The thermodynamic magnetization crossover effect from T 3/2 to T 2 occurs in the thick films due to the itinerant and localized characteristics of the 3d electrons of Co atoms. The temperature‐dependent SRT is found only in the 300‐nm‐thick film as the temperature increases from 5 to 400 K, whereas SRT has previously been shown to occur in the thick glassy films over a large thickness window. The thermodynamic magnetization crossover temperature shifts to a high temperature as the film thickness increases. As the film thickness decreases to 20 nm, the crossover effect disappears, and magnetization varies with temperature following the T 2 law in the temperature range from 5 to 400 K. The low‐temperature SRT in the CoSiB alloy is due to the strong spin–orbit coupling, which is responsible for the low‐temperature out‐of‐plane anisotropy. The transition from low to high resistance provides evidence for the presence of localized 3d electrons in Co atoms.