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Ethan R. Cronk

Publications and source records attributed to Ethan R. Cronk.

2 recordsLinked to original sources

Growth of (111)-textured SrTiO3 thin films on Pt(111)/Al2O3(1-102) substrates by rf magnetron sputter deposition

SrTiO3 thin films, 20-30nm, with high quality crystal structure and low roughness can be used as growth templates for complex oxides or as the dielectric materials for capacitor structures. In this work, stoichiometric STO thin films were grown by radio frequency magnetron sputtering on Pt (111) templates grown on rAl2O3 substrates, and the effects of growth parameters as well as the underlying Pt templates structural properties on the quality of STO films were studied. A comparison between room temp grown Pt and Pt grown at elevated temps showed that the latter lead to highly ordered Pt and STO films with quasi 2D surface roughness. Xray diffraction showed that the STO thin films had (111) and (222) crystal orientation. A rocking curve full width at half maximum value of 0.2° was achieved, indicating that the STO films are high-quality. The STO films have a roughness less than 1 nm, as measured using atomic force microscopy, comparable to the underlying Pt templates roughness.

cond-mat.mtrl-sci

Thermal Corrections and Analysis on the Phase Stability of CsPbCl3 and Cs2AgSbCl6 during In-Situ Thermal Treatment

Cesium lead chloride (CsPbCl3) is a well known and principal model for inorganic perovskite halide optoelectronic research. The many available techniques including high temperature stability testing have been used to investigate the increasing interest in inorganic perovskites as primary layers in solar cell applications. Due to the nature of high temperature testing, the characterization technique, reproducibility, and the true sample temperature are vital in determining relative stability. By choosing CsPbCl3 in the investigation of the structural stability of perovskites at high temperatures, it acts as a baseline to create and verify a methodology that accurately probes sample temperature, phase transitions, and decomposition onsets. Therefore, we present a methodological approach to investigate the thermal interactions and stability of CsPbCl3 as a parent single perovskite halide based on ligand-assisted re-precipitation synthesis techniques. Where we use our approach to inform and probe thermal interactions in other cesium/chlorine compounds like Cs2AgSbCl6. By analyzing the stoichiometry and initial phases through investigations of the crystalline structure and particle morphology, we calculated temperature conversions using a control substrate and refinements to best estimate changing structure parameters. Using in-situ temperature dependent X-ray diffraction, we were able to effectively probe the phase transitions and decomposition temperatures of the investigated halide powders. Creating a process that can confirm known high temperature structural phenomena of model perovskite halides while verifying our true sample temperature. Which allowed for further testing on the thermal kinetics of on the double perovskite structure Cs2AgSbCl6 and will continue to allow us to test other perovskites and perovskite families of interest in modern high temperature perovskite halide research.

cond-mat.mtrl-sci