Magnetostriction Behaviors of Single- and Poly-Crystalline Ni/Ni-Co Bi-Layer Films

抄録

  Ni(t_Ni nm)/Ni₅₀Co₅₀(100–t_Ni nm) bi-layer films are prepared on Cu/Pd/MgO(001) single-crystal substrates at 300 ℃ and on Cu/Pd/glass substrates at room temperature by varying the layer thickness, t_Ni, in a range of 0–100 nm. The effect of layer thickness ratio on the magnetostriction is investigated. As t_Ni value increases from 0 to 100 nm, the magnetostriction coefficient observed for single-crystal film along fcc[100], λ₁₀₀, monotonically decreases from a positive value of +1 × 10^–4 (t_Ni = 0 nm) to a negative value of –6 × 10^–5 (t_Ni = 100 nm), whereas that measured along fcc[111], λ₁₁₁, remains almost similar (–4 × 10^–5 to –2 × 10^–5). The magnetostriction coefficient of poly-crystalline film decreases from –3 × 10^–6 to –2 × 10^–5 with increasing t_Ni value from 0 to 100 nm. The present study has shown that control of magnetostriction coefficient is possible by combining materials with positive and negative coefficients.