中文摘要：

多铁性六方锰氧化物RMnO3（R=Y，H0-Lu）具有丰富的结构与物理内涵，是近年来凝聚态物理与材料科学领域的研究热点。本文利用透射电子显微术对钇稳定氧化锆（yttria—stabilized zirconia，YSZ）基底上外延生长的HoMnO，薄膜的微结构进行表征。研究结果表明，C轴取向的HoMnO3薄膜可以在YSZ（111）基底上实现良好的外延。薄膜中的主要缺陷为异相边界（out-of-phase boundary，OPB）。OPB的产生归因于表面台阶机制和形核层机制。OPB缺陷处会出现化学计量比失衡，实验上观察到富Ho和富Mn两种类型的OPB，这些化学计量比失衡的缺陷会对薄膜的电学性能产生影响。本文研究结果有助于深入理解六方锰氧化物薄膜结构与物理性能之间的关系。

英文摘要：

Recently, multiferroic hexagonal manganites RMnO3 （ R = Y, Ho-Lu） has been a hot topic in the area of both condensed matter physics and materials science due to their rich connotation in structure and physical properties. Using transmission electron microscopy, the microstructure of muhiferroic HoMnO3 epitaxial thin films grown on yttria-stabilized zirconia （YSZ） substrates was studied. It is shown that high quality c-axis oriented HoMnO3 thin films are successfully grown on YSZ （ 111 ） substrates. Major defects in the films are out-of-phase boundaries （ OPBs）. The formation of OPBs is ascribed to the surface step mechanism and the nucleation layer mechanism. Scanning transmission electron microscopy investigations indicate that the OPBs are off-stoichiometric, either Ho rich or Mn rich. Such off-stoichiometric defects may affect the electrical properties of the films. These findings may be helpful for future thin film growth and further understanding of the correlation of structure and physical properties in hexagonal manganite thin films.