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1. One-Step Solvothermal Synthesis of Perovskite-Type Li _3x La _2/3–x □ _1/3–2x TiO ₃ Nanomaterials

   https://doi.org/10.1021/acs.chemmater.4c01349  

   Dato, Michael A; Hu, Linhua; McElheny, Dan; Cabana, Jordi (September 2024, Chemistry of Materials)
2. Band Alignment of Al ₂ O ₃ on α-(Al _x Ga _1-x ) ₂ O ₃

   https://doi.org/10.1149/2162-8777/ac546f  

   Xia, Xinyi; Al-Mamun, Nahid Sultan; Fares, Chaker; Haque, Aman; Ren, Fan; Hassa, Anna; von Wenckstern, Holger; Grundmann, Marius; Pearton, S. J. (February 2022, ECS Journal of Solid State Science and Technology)

   X Ray Photoelectron Spectroscopy was used to measure valence band offsets for Al 2 O 3 deposited by Atomic Layer Deposition on α -(Al x Ga 1-x ) 2 O 3 alloys over a wide range of Al contents, x, from 0.26–0.74, corresponding to a bandgap range from 5.8–7 eV. These alloys were grown by Pulsed Laser Deposition. The band alignments were type I (nested) at x <0.5, with valence band offsets 0.13 eV for x = 0.26 and x = 0.46. At higher Al contents, the band alignment was a staggered alignment, with valence band offsets of − 0.07 eV for x = 0.58 and −0.17 for x = 0.74, ie. negative valence band offsets in both cases. The conduction band offsets are also small at these high Al contents, being only 0.07 eV at x = 0.74. The wide bandgap of the α -(Al x Ga 1-x ) 2 O 3 alloys makes it difficult to find dielectrics with nested band alignments over the entire composition range. 

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3. MOCVD growth of β-phase (Al _x Ga _1−x ) ₂ O ₃ on ( 2 ¯01) β-Ga ₂ O ₃ substrates

   https://doi.org/10.1063/5.0025478  

   Bhuiyan, A F; Feng, Zixuan; Johnson, Jared M.; Huang, Hsien-Lien; Hwang, Jinwoo; Zhao, Hongping (October 2020, Applied Physics Letters)

   null (Ed.)
4. Growth and characterization of (Sc ₂ O ₃ ) _x (Ga ₂ O ₃ ) _1−x by molecular beam epitaxy

   https://doi.org/10.1116/6.0001805  

   Hlad, Mark S.; Gila, Brent P.; Abernathy, Cammy R.; Ren, Fan; Pearton, S. J. (July 2022, Journal of Vacuum Science & Technology A)

   (Sc 2 O 3 ) x (Ga 2 O 3 ) 1−x was grown by molecular beam epitaxy at low temperatures (100 °C) using a variety of growth sequences to avoid surface segregation of Ga. Continuous and digital growth techniques always produced Ga segregation. This surface segregation was attributed to the stronger bond between the Sc and O compared to the Ga and O. A digital growth technique (alternate opening of Sc and Ga shutters with the O shutter open continuously during the growth) was unsuccessful in eliminating this effect. The segregation was eliminated using a growth technique in which the Ga shutter was closed for a set amount of time toward the end of the growth while the O and Sc shutters remained open. Characterization with reflection high energy electron diffraction, x-ray diffraction, and transmission electron microscopy revealed the growth of a fine-grained polycrystalline film under these conditions. A third growth technique was used that involved closing the Ga shutter for a set amount of time toward the end of the growth while the O and Sc shutters were open continuously. This technique was successful in depositing a uniform film. However, the breakdown field was only 1.40 MV/cm (at 1 mA/cm 2 ). The addition of Ga to Sc 2 O 3 diminished the insulating properties of the film. These initial experiments indicate that phase segregation is likely to be a major issue with most growth techniques and that alloying Ga 2 O 3 with elements other than Sc, such as Gd or Al, might be a more successful approach. 

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5. Ca-repaired BaZrO ₃ nanorods/YBa ₂ Cu ₃ O _7-x interface for enhanced pinning in YBa ₂ Cu ₃ O _7-x nanocomposites with 2-8% BaZrO ₃ doping

   https://doi.org/10.1088/1757-899X/1302/1/012013  

   Wu, Judy; Panth, Mohan; Ogunjimi, Victor; Ann_Sebastian, Mary; Zhang, Di; Haugan, Timothy; Wang, Haiyan (May 2024, IOP Conference Series: Materials Science and Engineering)

   Abstract C-axis aligned BaZrO₃(BZO) nanorods formed via strain-mediated self-assembly in BZO-doped YaBa₂Cu₃O_7-x(BZO/YBCO) nanocomposite films can provide strong pinning to the quantized magnetic vortices. While the strain initiated from the BZO/YBCO lattice mismatch plays a critical role in nucleation and evolution of the BZO nanorods, it also leads to a highly defective BZO/YBCO interface and hence reduced pinning efficiency of BZO nanorods. This work reports a recent study in probing the effect of BZO/YBCO interface on the pinning efficiency of the BZO nanorods as the interface is repaired dynamically during the BZO nanorod growth using Ca doping. Within the BZO doping range of 2-8 vol.%, significantly enhanced pinning efficiency of the BZO nanorods have been observed. A peak enhancement up to five-fold of critical current density at 9.0 T and 65-77 K has been obtained in the 6 vol.% BZO/YBCO nanocomposites after the interface repair. This result not only illustrates the critical importance of the BZO/YBCO interface in the pinning efficiency, but also provides a facile scheme to achieve such an interface to restore the pristine pinning efficiency of the BZO nanorods. 

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