我们使用PLD方法在SrTiO3衬底上生长了CaRuO3薄膜。TEM表征显示CaRuO3薄膜具有有应变的立方结构和正交结构,我们发现由于部分CaRuO3具有立方结构,所以我们的薄膜显示一定的铁磁性。而一般体相的CaRuO3是没有磁性的。以上磁性也通过第一性原理计算获得验证。另外,我们还讨论了CaRuO3薄膜的形成机理。

本论文发表在APL。

全文链接: http://apl.aip.org/resource/1/applab/v96/i18/p182502_s1

4 May, 2010

  

 

 

Topological insulators represent a new state of quantum matter recently discovered with insulating bulk but conducting surface states formed by an odd number of Dirac fermions. In this Letter, we report our recent progress on the study of electronic structures of ex-situ grown topological insulator thin films by angle resolved photoemission spectroscopy (ARPES). We successfully obtained the topological band structures of molecular beam epitaxial HgTe and vapor–solid grown Bi2Te3 thin films after proper surface cleaning procedures. This new development will not only enable us to study more topological insulators that cannot be measured by conventional in-situ ARPES technique (e.g. by cleaving or growing samples in-situ), but also open the door to directly characterize the electronic properties of topological insulators used in functional devices.

文章作为封面,发表在physica status solidi-Rapid Research Letters 7, 130 (2013)

全文链接:http://onlinelibrary.wiley.com/doi/10.1002/pssr.201206400/abstract

封面链接:http://onlinelibrary.wiley.com/doi/10.1002/pssr.201390000/abstract

pss

我们用PLD在SrTiO3(001)衬底上沉积了高质量的外延nLaFeO3–Bi4Ti3O12 (n = 0.5,1.0,1.5) 薄膜。XRD和TEM表征表明我们合成的n=0.5和1.5的薄膜元胞内具有奇-偶层氧八面体的特点,而n=1.0的薄膜元胞全部是偶数层氧八面体。其中 n = 0.5 和 1.5 的样品具有明显的室温亚铁磁性,但是n=1.0的样品是反铁磁的。

本论文发表在APL.

全文链接: http://apl.aip.org/resource/1/applab/v98/i21/p212501_s1

23 May, 2011

  

 

 

A series of LaFeO3/YMnO3 superlattices with various thicknesses are synthesized epitaxially on (001) and (111) SrTiO3 substrates. X-ray diffraction, high-resolution cross-sectional transmission electron microscopy, and sub-nanometer-scale resolved electron energy loss spectroscopy characterizations prove that grown superlattices have designed layer-by-layer structures, and there is atomically sharp interface between two successive constituent layers. Temperature-dependent magnetization and magnetic hysteresis loop measurements substantiate that there is significant ferrimagnetism generated at  LaFeO3/YMnO3 interfaces. The generated ferrimagnetism is discussed by considering the magnetic structures in each constituent layer.

YMO LFO TEM

YMN-LFO

本文章发表在Appl. Phys. Lett. 102, 042403 (2013).

全文链接:http://apl.aip.org/resource/1/applab/v102/i4/p042403_s1