High pressure floating-zone growth and property characterization of Cr-doped hexagonal YMnO3 crystals

Large crystal growth of Cr-doped h-YMnO3 has been investigated by using a high pressure optical floating-zone method. The size of the grown crystals is typically 60-70 mm in length and 4-5 mm in diameter. The structure of the grown crystals is analyzed by powder X-ray diffraction and scanning electron microscopy. The defects in the as-grown crystals, including low-angle grain boundary and inclusions are studied. An off-stoichiometric phenomenon is found with a slight Cr deficiency in different parts. The relationship between defects and growth conditions during crystal growth is also discussed. The magnetic properties show spin-glass phase features with weak ferromagnetic behavior below 30 K.