Magnetic and transport studies of core–shell nanorods based on metallic oxide ferromagnet SrRuO3. (January 2016)

• Record Type: Journal Article
• Authors: Zheng, M.; Li, X.Y.; Zhu, Q.X.; Li, H.R.; Shi, L.; Li, X.M.; Zheng, R.K.
• Is Part Of: Superlattices and microstructures. Volume 89(2016)
• Page Start: 336
• Page End: 344
• Publication Date: 2016-01
• Subjects: Core–shell nanorods -- Magnetic properties -- Electrical properties -- Ohmic contact; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2015.11.027
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: This study presents the synthesis of perovskite metal-semiconductor core–shell heterostructures by sputtering SrRuO3 (SRO) shell layer on vertically aligned hydrothermally produced ZnO nanorods. Compared to the two-dimensional SRO films, the magnetic behaviors of the SRO shells on ZnO nanorods are morphology and thickness dependent, as reflected by the magnetic isotropy effects and the appearance of double-step magnetic hysteresis loops caused by nanograin-induced disorder and uncompensated spin at the surface and interface. The appearance of low-temperature resistance minimum and the good fitting of the low-temperature resistance data to a theoretical model establish the emergence of weak localization effect in the SRO shells, whose strength can be reinforced by a magnetic field. In addition, an apparent low-resistance Ohmic contact was realized in the ZnO/SRO heterojunctions due to the lower work function of the SRO. This, together with the absence of the Schottky barrier at the interface, demonstrates that the ZnO/SRO nanostructures could hold great promise for applications in advanced electron field emitters. Graphical abstract: Ohmic contact has been achieved for ZnO/SrRuO3 core–shell heterojunctions prepared by sputtering SrRuO3 shell layer on vertically aligned hydrothermally produced ZnO nanorods, which also show interesting phenomena such as weak localization effect and double-step magnetic hysteresis loops at low temperatures. Highlights: ZnO/SrRuO3 core–shell nanorods have been fabricated via a combination process. The core–shell nanorods show magnetic isotropy behavior. The core–shell nanorods show nanograin-induced double-step magnetic hysteresis loops. Magnetic field could enhance the weak localization effects in SrRuO3 shells. The ZnO/SrRuO3 heterojunctions show an Ohmic behavior of the resistance.