X-Ray Truncation Rod Analysis of the Reversible Temperature Dependent Surface Structure of LAALO3
The surface structures, compositions, and terminations of ABO3oxides with the perovskite structure are of major importance due to their extensive use as substrates for thin film growth, in particular for the growth of superconducting films of materials such as YBa2Cu3O7. LaA1O3is particularly attractive in this regard since its lattice mismatch with YBa2Cu3O7is small (<2%), and its high melting point (2453K) minimizes interfacial dislocations and chemical reactions with the films.’ To facilitate its use as a growth substrate the surface structure and composition of LaA1O3should be thoroughly characterized. LaAIO3 has a bulk rhombohedral perovskite structure at room temperature and undergoes a transformation to a simple cubic structure at about 710K2although several groups have reported that the change occurs gradually between room temperature and 770K.2-4This transformation involves changes in bond angles of only tenths of a degree and microtwinning is not observed.
KeywordsMigration Hydrate Platinum Tungsten Perovskite
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