Zhenzhen Hui

Solution processing of transparent conducting epitaxial La:BaSnO3 films with improved electrical mobility

As a type of perovskite transparent conducting oxides, La-doped BaSnO3 is considered as a very important material to construct all transparent perovskite devices. The difficulty in achievement of large-area films with high electrical mobility has hindered the development of La-doped BaSnO3 films. Here, we report the results about chemical solution deposition of Ba0.92La0.08SnO3−δ (BLSO) films. The post-annealing and atmosphere as well as lattice mismatch have been investigated. Post-annealing at 1000 °C can obviously improve the performance due to the enhanced crystallization. Under post-annealing in N2 atmosphere the room-temperature resistivity and electrical mobility can achieve 3.25 mΩ cm and 11.09 cm2 V−1 s−1, respectively, for the BLSO on LaAlO3 single crystal substrates due to the enhanced oxygen deficiencies. BLSO films with different orientation can be easily obtained by selection of the substrates, showing isotropic physical properties. Furthermore, the room-temperature resistivity and mobility ...

Magneto-acceleration of Ostwald ripening in hollow Fe3O4 nanospheres

The magnetic field-induced acceleration of the Ostwald ripening process was demonstrated firstly in the formation of hollow Fe3O4 nanospheres. Similar to the maintaining time, the magnetic field can act as an independent parameter to control the crystallite size, hollow structure, and pore size of nanostructures in the Ostwald ripening process.

Self-assembled c-axis oriented antiperovskite soft-magnetic CuNCo3 thin films by chemical solution deposition

Preparation of antiperovskite thin films is challenging work due to their complex phase diagram and easy decomposition during processing, which hinder the fundamental studies and applications. Herein, we report the preparation of antiperovskite CuNCo3 (CNC) thin films on several different single crystal substrates by chemical solution deposition. The results show that the derived CNC thin films are c-axis oriented regardless of the substrate orientation, suggesting the self-assembled c-axis orientation. The microstructures as well as the physical properties are investigated, showing that the CNC thin films are metallic and can be considered as a new type of soft-magnet with a ferromagnetic Curie temperature higher than 650 K. The results will provide an effective route for fabricating antiperovskite cobalt-based thin films as well as provide a prototype for the investigation of the growth mechanisms of complex metal nitride thin films by solution methods.

Facile chemical solution deposition of nanocrystalline CrN thin films with low magnetoresistance

CrN thin films are first prepared by a facile chemical solution deposition method. The results show that the derived CrN thin films are nanocrystalline with the grain size of 30–60 nm. X-ray photoelectron spectroscopy measurement shows the stoichiometry of the derived thin film. The temperature dependent resistivity within the range of 2–300 K shows a semiconductor-like behavior with dρ/dT < 0 and a discontinuity in resistivity at 253 K is observed due to the antiferromagnetic transition. At 10 K the magnetoresistance is as low as −0.06% under 45 kOe. The first growth of CrN thin films by the facile chemical solution deposition will provide an alternative route to prepare CrN thin films, especially for large-area CrN thin films with low-cost.

Upper critical field and vortex phase diagram of polycrystalline δ-Mo1-xZrxN thin films by sol-gel

Upper critical field of polycrystalline δ-Mo1-xZrxN (0 ≤ x ≤ 0.3) thin films by sol-gel was investigated. It showed that the upper critical field was continuously improved with Zr doping content, and the improvement of ∼10 T in upper critical field was mainly attributed to the combined effects of obvious enhancements in normal-state resistivity with slight changes in Tc, obvious decrease in crystallite/grain size and enhanced microstrains. Flux jump was observed in low-level doped thin films due to enhanced critical current density by Zr doping. Finally, the vortex phase diagram of δ-Mo0.95Zr0.05N thin films was presented, which will provide guidance for investigation about the vortex mechanisms of δ-Mo1-xZrxN thin films.