Papers by Author: Hyun Young Go

Abstract: We investigated electrical properties of epitaxial Mn doped bismuth ferrite BiFe0.97Mn0.03O3 (BFMO) thin films with different crystal orientations deposited on Si substrates with appropriate buffer layers. Epitaxial SrRuO3 (SRO) thin films with (001), (101), and (111) orientations were grown on CeO2/yttria-stabilized zirconia (YSZ)/Si(001) substrates and YSZ/Si(001), respectively, by the insertion of MgO and TiO2 atomic layers using pulsed-laser deposition (PLD). Using spin coating, we deposited BFMO thin films onto orientated SRO thin films. The BFMO orientation followed the SRO orientation. The Pr values of the BFMO were ordered as follows {111}>{110}>{100}, which is the same as that predicted by crystallographic considerations. The largest Pr value of the {111} orientation is 76 μC/cm2 at 100 kHz, 25°C.

Abstract: In this study, BiFeO3 (BFO) epitaxial film was deposited on SrRuO3 (100)/SrTiO3 (100) substrates using pulsed laser deposition (PLD). Phase pure BFO thin film was obtained. Introducing a mask between the target and substrate in PLD improved the surface roughness from 47.8 nm (RMS, without mask) to 7.7 nm (RMS, with mask). The composition and electrical properties of BFO thin film were assessed after annealing for 1 h in Ar, N2, or O2 atmosphere at 600°C. The P-E hysteresis properties improved only in the O2 atmosphere. After annealing under O2 atmosphere, the leakage current decreased from 6.1 × 10-2 A/cm to 2.9 × 10-2 A/cm at 200 kV/cm, as in the other annealing atmospheres, but 2Pr increased from 35 BC/cm2 to 50 BC/cm2.