In this work, p-n junctions are made from directly depositing optimal doped La1.85Sr0.15CuO4 (LSCO) films on n-type Nb-doped SrTiO3 substrates. Film thickness controlled rectifying behaviors are strikingly displayed...In this work, p-n junctions are made from directly depositing optimal doped La1.85Sr0.15CuO4 (LSCO) films on n-type Nb-doped SrTiO3 substrates. Film thickness controlled rectifying behaviors are strikingly displayed. The starting points of the diffusion voltage reduction Vd-on change clearly with varying film thickness. Vd-on and Tc coincide with each other when the film thickness is larger than 300 nm, indicating a close relation between the two parameters. However, when the film is very thin (〈 350 nm) a departure between the two parameters was also observed. A possible reason for this is discussed within the framework of an inhomogeneous Sehottky contact. Enhanced interface inhomogeneity due to the tensile strain appears to be the origin.展开更多
In this paper we report a new method to fabricate nanostructured films, La0.67Ca0.33MnO3 (LCMO) nanostructured films have been fabricated by using pulsed electron beam deposition (PED) on anodized aluminium oxide ...In this paper we report a new method to fabricate nanostructured films, La0.67Ca0.33MnO3 (LCMO) nanostructured films have been fabricated by using pulsed electron beam deposition (PED) on anodized aluminium oxide (AAO) membranes, The magnetic and electronic transport properties are investigated by using the Quantum Design physics properties measurement system (PPMS) and magnetic properties measurement system (MPMS). The resistance peak temperature (Tp) is about 85 K and the Curie temperature (To) is about 250 K for the LCMO film on an AAO membrane with a pore diameter of 20nm. Large magnetoresistance ratio (MR) is observed near Tp. The MR is as high as 85% under 1 T magnetic field. The great enhancement of MR at low magnetic fields could be attributed to the lattice distortion and the grain boundary that are induced by the nanopores on the AAO membrane.展开更多
Characterization of Fermi surface of the BaSn3 superconductor(Tc~ 4.4K)by de Haas–van Alphen(dHvA)effect measurement reveals its non-trivial topological properties.Analysis of non-zero Berry phase is supported by the...Characterization of Fermi surface of the BaSn3 superconductor(Tc~ 4.4K)by de Haas–van Alphen(dHvA)effect measurement reveals its non-trivial topological properties.Analysis of non-zero Berry phase is supported by the ab initio calculations,which reveals a type-II Dirac point setting and tilting along the high symmetric K–H line of the Brillouin zone,about 0.13 eV above the Fermi level,and other two type-I Dirac points on the high symmetric Г–A direction,but slightly far below the Fermi level.The results demonstrate BaSn3 as an excellent example hosting multiple Dirac fermions and an outstanding platform for studying the interplay between nontrivial topological states and superconductivity.展开更多
基金Supported by the Key Project Foundation of Science and Technology of He'nan Province (092102210166) and the Natural Science Foundation of He'nan Provincial Educational Department (2008A140013, 2010B140015)
文摘In this work, p-n junctions are made from directly depositing optimal doped La1.85Sr0.15CuO4 (LSCO) films on n-type Nb-doped SrTiO3 substrates. Film thickness controlled rectifying behaviors are strikingly displayed. The starting points of the diffusion voltage reduction Vd-on change clearly with varying film thickness. Vd-on and Tc coincide with each other when the film thickness is larger than 300 nm, indicating a close relation between the two parameters. However, when the film is very thin (〈 350 nm) a departure between the two parameters was also observed. A possible reason for this is discussed within the framework of an inhomogeneous Sehottky contact. Enhanced interface inhomogeneity due to the tensile strain appears to be the origin.
基金Project supported by the key program of Natural Science Foundation of Zhejiang Provincial, China (Grant No Z605131), National Natural Science Foundation of China (Grant No 60571029), the ‘Hundred Talents Project' of Chinese Academy of Sciences, China, the Creative Research Group of the National Natural Science Foundation of China (Grant No 60321001).
文摘In this paper we report a new method to fabricate nanostructured films, La0.67Ca0.33MnO3 (LCMO) nanostructured films have been fabricated by using pulsed electron beam deposition (PED) on anodized aluminium oxide (AAO) membranes, The magnetic and electronic transport properties are investigated by using the Quantum Design physics properties measurement system (PPMS) and magnetic properties measurement system (MPMS). The resistance peak temperature (Tp) is about 85 K and the Curie temperature (To) is about 250 K for the LCMO film on an AAO membrane with a pore diameter of 20nm. Large magnetoresistance ratio (MR) is observed near Tp. The MR is as high as 85% under 1 T magnetic field. The great enhancement of MR at low magnetic fields could be attributed to the lattice distortion and the grain boundary that are induced by the nanopores on the AAO membrane.
基金Supported by the National Natural Science Foundation of China(Grant No.11874264)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA18000000)+3 种基金the Starting Grant of Shanghai Tech University,the Shenzhen Peacock Team Plan(Grant No.KQTD20170809110344233)the Bureau of Industry and Information Technology of Shenzhen through the Graphene Manufacturing Innovation Center(Grant No.201901161514)the Key Scientific Research Projects of Higher Institutions in Henan Province(19A140018)Analytical Instrumentation Center,SPST,Shanghai Tech University(Grant No.SPST-AIC10112914).
文摘Characterization of Fermi surface of the BaSn3 superconductor(Tc~ 4.4K)by de Haas–van Alphen(dHvA)effect measurement reveals its non-trivial topological properties.Analysis of non-zero Berry phase is supported by the ab initio calculations,which reveals a type-II Dirac point setting and tilting along the high symmetric K–H line of the Brillouin zone,about 0.13 eV above the Fermi level,and other two type-I Dirac points on the high symmetric Г–A direction,but slightly far below the Fermi level.The results demonstrate BaSn3 as an excellent example hosting multiple Dirac fermions and an outstanding platform for studying the interplay between nontrivial topological states and superconductivity.