The structural properties and Morin transition in c-plane-oriented α-Fe2O3 and Ir-doped α-Fe2O3 thin films have been investigated. The enhancement of the Morin transition temperature (TM) in α-Fe2O3 film by Ir doping has been demonstrated. The TM in the c-plane-oriented α-Fe2O3 thin film was determined from the temperature-dependent in-plane magnetization and change of coercivity (Hc); this TM value was found close to that of bulk α-Fe2O3. The spin directions of non-doped and Ir-doped α-Fe2O3 at room temperature were also estimated from conversion electron Mössbauer spectroscopy measurements. We confirmed that Ir doping dramatically enhances the TM of α-Fe2O3 thin film.

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Flexible and polarizable molecular dynamics simulations are carried out to elucidate the structure and vibrational sum frequency generation (SFG) spectra of two water/organic liquid interfaces: water/carbon tetrachloride (CCl 4 ) and water/1,2dichloroethane (DCE). Preceding experimental spectra by Richmond and co-workers have shown quite contrasting features of the two SFG spectra. The former spectrum is analogous with that of water/vapor interface with two-band structure, while the latter is structureless without feature of the dangling OH bond. The present calculations well reproduced these experimental features, though the orientational structure of interfacial water is found to be qualitatively similar. The structureless spectrum of the water/DCE is elucidated with considerable local interaction between water and DCE molecules at the interface, which results in red shift and broadening of the dangling OH band of the interfacial water directing toward the DCE phase.

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In this study, we fabricated a Cr 2 O 3 (0001) film without and with a Pt buffer layer and investigated its effect on perpendicular exchange coupling in a Cr 2 O 3 /Co 3 Pt interface. The results showed that the exchange bias field (l 0 H ex ) and blocking temperature (T B ) of a Cr 2 O 3 film without and with Pt were very different. The Cr 2 O 3 film without Pt had a lower l 0 H ex of 176 Oe and a lower T B of 75 K, whereas that with Pt had a higher l 0 H ex of 436 Oe and a higher T B of 150 K. We discussed this difference in l 0 H ex and T B values based on collinear/non-collinear coupling in a ferromagnetic and antiferromagnetic interface using Meiklejohn and Bean's exchange anisotropy model. V C 2013 American Institute of Physics. [http://dx