Modulation of Insulator-Metal Transition Temperature by Visible Light in La _7/8 Sr _1/8 MnO ₃ Thin Film

Abstract

Effects of magnetic field and light illumination on the electrical transport properties of La 7/8 Sr 1/8 MnO3 thin film grown on a Si substrate are investigated. The film shows an insulator-metal transition at 𝑇𝑃 ≈ 191.9 K and a low-temperature resistance minimum at 𝑇min ≈ 48 K in darkness. Both magnetic field and light illumination shift the insulator-metal transition temperature 𝑇𝑃 to be higher, while the low-temperature transport properties of the film induced by them show different trends. That is, the magnetic field and light illumination make the 𝑇min shift to lower and higher temperatures, respectively. The enhancement of both 𝑇𝑃 and 𝑇min under light illumination could be explained in terms of photoinduced hole-doping and demagnetization effects of La 7/8 Sr 1/8 MnO3.

Ultrafast phase separation dynamics in La0.875Sr0.125MnOMertelj1, Мамин2, Yusupov3 et al. 2011Phys. Rev. B

“…However the proximity of the FM phase at x 0.16, 8-10 high dielectric permittivity 16 of La 0.875 Sr 0.125 MnO 3 at higher temperatures, and photoconductivity in La 0.875 Sr 0.125 MnO 3 thin films 23 suggest that the free energy of the FM phase is close to the free energy of other phases and that the SF phase could be metallic.…”