Physical properties of multiferroic hexagonal HoMnO3 thin films

The authors investigated the magnetic and ferroelectric properties of hexagonally grown HoMnO3 thin films. The magnetic measurements revealed bulklike magnetic phase transitions with an additional spin-glass-like behavior feature below the Neel temperature. The ferroelectricity in the films was distinctly different from the suggested bulk behavior. Below 40 K, the HoMnO3 films showed typical ferroelectric character: their remnant polarization and coercive field values at 20 K were 3.7 mu C/cm(2) and 0.69 MV/cm. Above 40 K, however, the films exhibited an unusual antiferroelectriclike behavior, with more pronounced features appearing at higher temperatures. These intriguing physical properties make HoMnO3 films a potential candidate material for numerous future applications.