[18a-131-1~10] 10.1 Emerging materials in spintronics and magnetics (including fabrication and charactrization methodologies)

▲ [18a-131-9] Correlation between the bias dependence of tunneling anisotropic magnetoresistance and tunneling magnetoresistance in a La_0.67Sr_0.33MnO₃-based magnetic tunnel junction

〇Anh Duc Le¹, Takashi Yamashita¹, Hiroki Yamasaki¹, Daisei Araki¹, Masaaki Tanaka¹, Shinobu Ohya¹ (1.The univ. of Tokyo)

Keywords:Magnetic oxides, tunneling magnetoresistance, tunneling anisotropic magnetoresistance

La_0.67Sr_0.33MnO₃ (LSMO) is one of the most promising oxide materials for spintronic devices. Here in this work, using a magnetic tunnel junction (MTJ) consisting of LSMO [18 unit cell (u.c.)] / STO (10 u.c.) / LSMO (40 u.c.) grown on an STO (001) substrate by molecular beam epitaxy, we simultaneously probed the carrier-energy dependence of the anisotropy of the DOS, by measuring the magnetic-field-direction dependence of the tunneling anisotropic magnetoresistance (TAMR), and that of the magnetic-field-direction dependence of the tunneling magnetoresistance (TMR). When rotating H = 10 kOe in the film plane, dI/dV shows a change of about ±1.5%, which is dominated by two-fold symmetries along [100] and [110], indicating changes in DOSs of the LSMO layers when rotating their magnetizations. Interestingly, the directions of H at which the DOS reaches maximum rotates by 90° when the bias voltage V is changed through V_p ~ 0.08 V or V_n ~ -0.14 V, which is attributed to a transition of the band character of the tunneling carriers from the e_g to t_2g. Also, we have found that the θ_H-dependence of TMR changes with V. Using the TAMR data and the TMR data, we discuss their correlations in the presentation.