Enhanced magnetization and magnetoelectric coupling in hydrogen treated hexagonal YMnO3

The present article entitled “Enhanced magnetization and magneto-electric coupling in hydrogen treated hexagonal YMnO3” deals with the synthesis and structural/microstructural, magnetic and magnetoelectric characterization for air and hydrogen treated YMnO3. We synthesized single phase hexagonal YMnO3 at 700 °C and 1250 °C by sintering in Ar/H2 and air atmospheres, respectively. Magnetic measurements of the samples, synthesized by sintering at relatively lower temperature in Ar/H2 atmosphere, show the enhanced ferromagnetic behaviour at 10 K. M-H curve shows that the value of saturation magnetization (Ms) at 10 K is 8.04 emu/g for Ar/H2 sintered sample while it is 2.93 emu/g for the air sintered sample. Moreover, a weak ferromagnetic signal at room temperature has been observed in YMnO3 compound. Magnetization versus magnetic field (M-H) curves of hydrogen treated samples, measured at room temperature, show small kink in the linear variation near origin, possibly due to the presence of weak ferromagnetic interactions in the samples at room temperature. However, the polarization-electric field (P-E) curve shows weak ferroelectric characteristics for the Ar/H2 sintered samples. It is suggested that the enhanced ferromagnetism in Ar/H2 sintered sample originates from the presence of oxygen vacancies in the Ar/H2 sintered samples. Moreover, the magnetoelectric coupling coefficient at room temperature is improved to 106 mV/cm Oe for Ar/H2 sintered sample as compared to 96 mV/cm Oe for air sintered sample at 40 kHz ac magnetic field frequency.