Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by m...Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas(Ar), Ta/W/Co/Pt sample shows inplane magnetic anisotropy(IMA). When sputtering W target at a different amount of N_(2) and Ar atmosphere, it can induce perpendicular magnetic anisotropy(PMA) for proper N-doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N_(2) is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68×10^(5) J·m^(-3),which enhanced by about 400% than our past works(annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X-ray diffraction(XRD) and X-ray reflection(XRR) results demonstrate that N dopants can effectively promote the formation of b-W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X-ray electron spectroscopy(XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co3 d and N 2 p. This may be another important reason for the PMA formation.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2019YFB2005800)the National Science Foundation of China(Nos.51871017,51871018 and 52071025)+2 种基金Beijing Natural Science Foundation(No.2192031)the Fundamental Research Funds for the Central Universities(No.FRF-TP-19-011B1)the Foundation of Beijing Key Laboratory of Metallic Materials and Processing for Modern Transportation。
文摘Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas(Ar), Ta/W/Co/Pt sample shows inplane magnetic anisotropy(IMA). When sputtering W target at a different amount of N_(2) and Ar atmosphere, it can induce perpendicular magnetic anisotropy(PMA) for proper N-doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N_(2) is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68×10^(5) J·m^(-3),which enhanced by about 400% than our past works(annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X-ray diffraction(XRD) and X-ray reflection(XRR) results demonstrate that N dopants can effectively promote the formation of b-W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X-ray electron spectroscopy(XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co3 d and N 2 p. This may be another important reason for the PMA formation.
