Mechanism of Cu dopant in transition metal oxide Mn_(1.56)Co_((0.96-x)) Ni_(0.48)Cu_xO_(4+δ) (0 ≤ x ≤ 0.2) thin films

摘要

To identify the substitution of Cu element for cations in transition metal oxide AB(2)O(4) structure, we propose to investigate the structural, optical and magnetic properties of Cu-doped Mn(1.56)Co((0.96-x))Ni(0.48)Cu(x)O(4-delta )films with 0 <= x <= 0.2. The X-ray diffraction of Mn1.56Co(0.96-x)Ni0.48CuxO4-delta films indicates good crystallization and cubic spinel structure. Raman spectra show two peaks of F-2g and A(1g) vibration modes, and the peak position changes with Cu dopant. The transition temperatures T-p1, T-p2 shift towards lower temperature by Cu doping, and the saturation magnetization M s decreases monotonously. The results show that the substitution of Cu ions does not vary the crystal structure but changes the ratio of Mn3+/Mn-4(+). Our proposed way overcomes the difficulties to directly observe the atoms of Mn, Co, Ni, and Cu with closed sizes in microstructure, and it is instructive to further understand the conduction mechanism of doped manganese cobalt nickel oxides in theory.