Structural properties and resistive switching behaviour in Mg _xZn_1-xO alloy films grown by pulsed laser deposition

Mg_xZn_1-xO alloy films with Mg concentration ranging from 0 to 0.5 were fabricated by a pulsed laser deposition method. The effect of Mg content on the microstructure and resistive switching behaviour was investigated. It was found that the film structure changed from pure hexagonal to a coexistence of hexagonal and cubic with increasing Mg content from 0 to 0.5. In addition, the ratio of the high-resistance state to the low-resistance state improved from ∼14 to ∼2 × 108. Furthermore, rapid thermal annealing of the samples reduced the forming voltage from ∼18V to ∼10V. The resistive switching behaviour in the Mg_xZn_1-xO films was explained by the filament model based on the variation of band gap and crystalline grains induced by the Mg content modulation and the thermal treatment.