Electronic phase separation and the CMR effect in Pr1−xCaxMnO3 films on (001) vicinal SrTiO3 substrates

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2007-11, Vol.144 (1-3), p.78-82
• Main Authors: Moschkau, P., Schramm, S., Hoffmann, J., Fladerer, J., Jooss, Ch, Wu, L., Zhu, Y.
• Format: Article
• Language: English
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2007.07.106

Our previous work showed that Pr1-xCaxMnO3 (x=0.2-0.5) thin films reveal an electronic phase separation, in which the low-temperature phase is orbital- and charge-ordered of the Zener-polaron type [Ch. Jooss, T. Beetz, L. Wu, M. Beleggia, R. Klie, M. Schofield, Y. Zhu, S. Schramm, J. Hoffmann, submitted for publication]. Applying a magnetic field leads to a ferromagnetic and conducting phase, which gives rise to the colossal magneto resistance effect (CMR). In this article we show that the orbital- and charge-ordered state could be significantly modified by different kind of lattice defects. Quenched disorder, present after the film deposition, can suppress long-range ordering. In addition, extended defects like twin boundaries act as a nucleation center for ordered domains, i.e. the hysteretic properties depend on the density of these defects. Well-ordered artificial anti-phase boundaries (APB) can be introduced by an epitaxial growth on vicinal substrates, leading to anisotropic transport properties with respect to the orientation of the APB.