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In order to improve the multiferroic properties of BiFeO3 and to clarify the Y substitution effect, we use an Nd:YAG laser to grow Bi1-xYxFeO3 (BYFO) films on glass substrates at low deposition temperatures by pulsed laser deposition (PLD). Their phase structure, microstructure, ferroelectric and magnetic characteristics, and leakage mechanism are explored. The existence of the perovskite phase in BYFO films with x = 0.00–0.10 is confirmed. The structure is transformed from rhombohedral for x = 0.00 to pseudo-cubic for x = 0.05, and an additional phase, orthorhombic, is coexisted for x = 0.10. The microstructure and surface morphology analyses demonstrate a decrease in grain size and film roughness when the Y concentration is increased. The crystalline structure and grain size dominate the hardness of 6.5–10.1 GPa, as measured by nanoindenter. We attain good ferroelectric characteristics for BYFO films with x = 0.00–0.05, where the greatest remanent polarization (2Pr) of 102.6 µC/cm2 is achieved for x = 0.05, connected to minimizing leakage and oxygen vacancy suppression. The typical ferromagnetic behavior with increased saturation magnetization from 4.4 emu/cm3 to 6.5 emu/cm3 by Y substitution possibly attributed to the suppressed spiral spin structure of G-type antiferromagnetism. The mechanisms of electric conduction behavior as functions of Y content and growth temperature are also discussed. [ABSTRACT FROM AUTHOR]

We investigated the structure, ferroelectric, magnetic, and leakage characteristics of Bi0.95H0.05FeO3 (BHFO) polycrystalline films with H = Gd, Tb, Dy, Ho, and Er. Bi0.95H0.05FeO3 films were confirmed to mainly consist of the perovskite phase, and the phase structure belongs to the pseudo-cubic phase. The desired ferroelectric and ferromagnetic properties at the same time, the remanent polarization (2Pr) of 57–81 μC/cm2 and the saturation magnetization (Ms) of 11.6–21.3 emu/cm3, are obtained for Bi0.95H0.05FeO3 films. Lower 2Pr with smaller ionic radius of H is possibly related to limited ion movement because of the reduced volume of the unit cell in BHFO films. Low leakage current characteristics and leakage mechanisms in Bi0.95H0.05FeO3 films are also discussed. In aspect of the magnetic properties, H can significantly improve the magnetic properties of BFO by A-site substitutions due to the suppressed spiral structure and importantly the contribution of high magnetic moment of H ion. The results of this work suggests BHFO films is a good multiferroic material, especially the samples with H = Tb and Dy. [ABSTRACT FROM AUTHOR]

Gallium nitride (GaN) ultraviolet metal-semiconductor-metal photodetectors (PDs) grown on Si substrates were demonstrated. The dark current of PDs fabricated on Si substrates was substantially smaller in magnitude compared to identical devices prepared on sapphire substrates. With an incident wavelength of 359 nm, the maximum responsivities of the n--GaN MSM photodetectors with TiW and Ni/Au contact electrodes were 0.187 and 0.0792 A/W, corresponding to quantum efficiencies of 64.7% and 27.4%, respectively. For a given bandwidth of 1 kHz and a given bias of 5 V, the corresponding noise equivalent powers of our n--GaN MSM photodetectors with TiW and Ni/Au electrodes were 1.525×10-12 and 5.119×10-12 W, respectively. Consequently, the values of detectivity (D*) determined for devices with TiW and Ni/Au electrodes were then calculated to be 1.313×1012 and 3.914×1011 cm Hz0.5 W-1, respectively. [ABSTRACT FROM AUTHOR]

Contents: Amniotic fluid is a rich source of multipotent mesenchymal stem cells (MSCs). Amniotic fluid stem cells (AFSCs) have become a new source of stem cells; they have low immunogenicity and are easily harvested. For this reason, they may be useful in clinical tissue engineering. Moreover, AFSCs have anti‐inflammatory properties and can repair tissues. This study evaluated the utility of AFSC injection to treat bilateral ovarian dystrophy in Holstein‐Friesian cows. Bovine AFSCs (BAFSCs) were collected at slaughter from Holstein‐Friesian cows during the third or fourth month of pregnancy and cultured in vitro. The BAFSCs began to show a fibroblast‐like morphology. They were positive for β‐integrin, CD44, CD73, CD106 and Oct4 and negative for CD34 and CD45. After induction, the cells differentiated into mesodermal lineages. Bilateral ovarian dystrophy was confirmed by ultrasonography in 16 lactating cows. The subsequent experiment lasted 15 weeks. Serum was collected weekly to analyse progesterone concentrations, and weekly ultrasonography recorded ovarian changes. Each cow was equipped with an automatic heat detection system to facilitate oestrus observation and breeding records. The progesterone concentration of two cows in the treatment group (25%) significantly increased during weeks 10–15. On ultrasonography, the treatment group demonstrated mature follicles after BAFSCs injection, and foetuses were visualized approximately 40 days after artificial insemination (AI). Oestrus rates in the control and treatment groups were 0% (0/8) and 50% (4/8), respectively; pregnancy rates were 0% (0/8) and 25% (2/8), respectively. Calves were successfully delivered in both cases of pregnancy. These results show that BAFSCs can alleviate bovine ovarian dystrophy and restore fertility. [ABSTRACT FROM AUTHOR]