Domain Walls in Oxide Thin Films for Resistive Switching

ACEVEDO, W ROMÁN; SALVERDA, MART; DIEGO RUBI; S. FAROKHIPOOR; B NOHEDA

Congreso; 2018 Joint meeting of the DPG and EPS Condensed Matter Divisions; 2018

Ferroelastic domain walls in thin films of some complex oxides show a higher conductivity than the domains [1][3]. This effect is proposed to originate from the accumulation of ionic species at the domain walls due to the presence of strain gradients [2][3][4]. So far, conductivity has been measured locally in the out-of-plane direction by conductive AFM[1][3] and also in-plane, by macroscopic electrical measurements for both as-grown [4] and written [1] domain walls. It has also been shown that domain walls, when probed between top and bottom electrodes (out-of-plane direction), can show memristive behaviour[6]. However, the intrinsic conduction mechanisms of domain walls are still unknown.In our previous work [Reference to this work or not? [7] we proposed a model that accounts, for the electrical behavior measured in TbMnO3 thin films using macroscopic techniques, by assuming that the crystalline domain walls that are present in these films [8] are conducting. From the model, the value of the sheet resistance of the domain walls can be extracted. To further investigate the validity of this approach for other materials, we perform a similar analysis on systems incorporating thin films of BiFeO3 where the domain walls are already proven to be conducting. Our aim is to elucidate the intrinsic transport properties of the domain walls. References[1] J. Seidel et al., Nature Materials 8, 229 (2009) [2] E. Salje and H. Zhang, Phase Transitions 82, 452 (2009) [3] T. Rojac et al., Nature Materials 16, 322 (2017)[4] S. Farokhipoor and B. Noheda, Physical Review Letters 107, 127604 (2011)[5] Q. He et al., Physical Review Letters 108, 067203 (2012)[6] P. Maksymovych et al., Nano Letters 11, 1906 (2011)[7] W. Román et al. (in preparation)[8] S. Farokhipoor et al., Nature 515, 379 (2014)