High Resolution X-Ray Diffraction Analyses of (La,Sr)MnO<sub>3</sub>/ZnO/Sapphire(0001) Double Heteroepitaxial Films

Abstract

Thin films of (La,Sr)MnO 3 (LSMO) were deposited on ZnO underlayer on sapphire (Sap) substrate by ion beam sputtering at the growth temperatures from 650˚C to 750˚C with supply of either plasma oxygen or molecular oxygen. The epitaxial relationships of lattices and crystalline qualities of LSMO/ZnO/Sap double-hetero systems were extensively analyzed by means of X-ray diffraction techniques with a modern high resolution XRD system. The epitaxial growth of out-of-plane (110) phase of the LSMO overlayer on the (0001) ZnO underlayer on the (0001) sapphire substrate is promoted at the higher temperatures accompanying the suppression of other competitive growth of the LSMO (001) and (111) phases. The plasma oxygen supply more enhances this suppression of the LSMO (111) phase at 750˚C. The complex in-plane orientational relationships of these three phases were clarified by the precise analyses based on various measurements of high resolution out-of-plane XRD and in-plane XRD, pole figure, and reciprocal space mappings. They are summarized as follows. (111) phase were discussed. These relationships were confirmed also by the data analyses of out-of-plane wide-range reciprocal space mappings using the 2-dimensional X-ray detector.

Characteristics of Carrier Transport and Crystallographic Orientation Distribution of Transparent Conductive Al-Doped ZnO Polycrystalline Films Deposited by Radio-Frequency, Direct-Current, and Radio-Frequency-Superimposed Direct-Current Magnetron Sputtering

“…The depth profiles of Al concentration in AZO thin films were determined by SIMS measurements. The textures of the films were characterized by measurements of wide-range out-of-plane reciprocal space maps [ 14 , 16 , 17 , 44 ] and pole figures [ 14 , 16 , 17 , 45 , 46 , 47 , 48 ] using the SmartLab XRD system (Rigaku Corp, Tokyo, Japan) equipped with a PILATUS 100 K/R two-dimensional X-ray detector using Cu-K radiation (wavelength λ = 0.15418 nm; weighted average of Cu-Kα 1 λ = 0.154059 nm/Cu-Kα 2 λ = 0.15444 nm with an intensity ratio of 2:1). The width of the X-ray beam on the samples is 10 mm during XRD measurements.…”

“…Reciprocal space map measurements should have access to the lattice plane inclined at an angle of ψ . In general, owing to the geometrical restriction required to maintain the skew geometry ( θ /2 θ geometry), the sample was tilted about the χ -axis, while the two-dimensional detector was scanned in the time-delayed integration mode [ 44 , 49 ].…”

High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation

“…For a comprehensive analysis of the texture evolution, we carried out out-of-plane grazing-incidence XRD (GIXRD) measurements, where the X-ray incident beam angle ( ω ) was fixed at 0.35° and only the 2 θ axis was scanned [ 21 – 24 ]. The crystal structure of the films was characterized by out-of-plane wide-range reciprocal space maps (RSMs) obtained using the SmartLab high-resolution XRD system (Rigaku corp.) equipped with a PILATUS 100K/R two-dimensional (2D) X-ray detector using Cu-K ā (wavelength λ = 0.15418 nm) radiation [ 25 , 26 ]. The optical properties were measured using a spectrophotometer (Hitachi, U-4100) and a spectroscopic ellipsometer (SE; J.A.…”

High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation

“…For a comprehensive analysis of the texture evolution, we carried out out-of-plane grazing-incidence XRD (GIXRD) measurements, where the X-ray incident beam angle (ω) was fixed at 0.35°and only the 2θ axis was scanned [21][22][23][24]. The crystal structure of the films was characterized by out-of-plane wide-range reciprocal space maps (RSMs) obtained using the SmartLab highresolution XRD system (Rigaku corp.) equipped with a PILATUS 100K/R two-dimensional (2D) X-ray detector using Cu-K ā (wavelength λ = 0.15418 nm) radiation [25,26]. The optical properties were measured using a spectrophotometer (Hitachi, U-4100) and a spectroscopic ellipsometer (SE; J.A.…”