Magnetic properties of hexagonal YMnO3 nanoparticles were systematically investigated. It is found that zero-field cooled and field-cooled magnetization display divergences at low temperature and a spin-glass temperature of TSG of 43 K are undergone. The thermoremanent magnetization further confirms the spin-glass feature of the YMnO3, which is related to the surface effects resulting in uncompensated spin and suppression of antiferromagnetic order. In particular, the exchange-bias effect is attributed to an exchange coupling between an antiferromagnetic core and the spin-glassy shell or ferromagnetic surface spins of the nanoparticles, which depends on the cooling field, is very interesting for nanomagnetic devices applications.

Magnetic and electronic structure properties of Co-doped SnO2 nanoparticles synthesized by the sol-gelhydrothermal technique

We report here the electrical and UV‐photoelectrical performance of transparent indium zinc oxide (IZO) thin film transistors with solution‐processed zirconia (ZrO2) dielectric. The channel layers were deposited by magnetron sputter at room temperature. The ZrO2 dielectric was deposited by solution process under ambient conditions followed by low temperature annealing. The films were structurally characterized by X‐ray diffraction and atomic force microscope. Good device characteristics have been obtained with a field effect mobility of 30.7 cm2 V−1s−1, a current on/off ratio of 105, a threshold voltage of 0.8 V, and a sub‐threshold swing of 30 mV decade−1. A resistor‐load inverter was fabricated and shows reasonable transfer characteristics with a gain of about 5 at supply voltage of 2 V. It was observed that the transistors are sensitive to UV illumination. When exposed to ultraviolet light with an intensity of 120 µW cm−2, the photo‐to‐dark current ratio was more than 104 in the depletion region. All the above features make IZO thin film transistor a promising candidate to be also used as a UV‐photo transistor.

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