Growth and electronic structure of LTO/STO heterostructure: Multi-modal studies*

LTO/STO interfaces have interesting features including 2-DEG, superconductivity and magnetism. These systems may realize complex-oxide based electronic devices. LTO is supposed to be insulators. However, PLD produced films, under compressional stress, behave like metal. It also undergoes transition to a Mott insulator below -145° C. Advanced photon source has beamlines suited for complex oxide studies. Sector-33 oxide-MBE allows operando studies of x-ray diffraction and RHEED measurements during the growth of oxide films. One can also transfer the sample in a UHV vacuum suitcase to soft-xray ARPES station at the beamline 29. Soft-xray ARPES provides significant enhancement in the penetration depth and one can study the interfaces in addition to the surfaces of samples. Deposition by alternating lanthanum and titanium did not produced pure phase of LaTiO3. Interestingly, the 6 unit cell sample from alternating deposition showed 2-DEG features in ARPES. LaTiO3 films could be successfully produced through codeposition of lanthanum and titanium. However, x-ray diffraction measurements showed the films from codeposition easily became rough after the growth.