Atomic and electronic band structures of Ti-doped Al2O3 grain boundaries
Source abstract
Abstract
Abstract Doping is one of the most popular strategies to modify the properties of polycrystalline materials, because the dopants prefer to segregate at the grain boundaries (GBs) and influence the structural and electronic properties of the materials. Understanding how dopants segregate at GBs and how they affect the resultant GB properties are essential. Here, we experimentally characterized the atomic structures and the electronic band structures of Ti-doped Σ7 { 4 5 ¯ 10 } and Σ7 { 2 3 ¯ 10 } GBs in α-Al2O3 by atomic resolution scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDXS) and valence electron energy-loss spectroscopy (EELS). It was found that Ti preferentially segregated at specific atom sites driven by ionic size mismatch between Ti3+ and Al3+, which leads to structural transformations in both GBs. Direct valence EELS measurement revealed the segregation of Ti3+ ions introduces impurity band within the bandgap in Al2O3 GBs. These results provide an in-depth understanding of the local atomic and electronic band structures for Ti-doped GBs.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Semiconductor materials and devices · Electronic and Structural Properties of Oxides · Semiconductor materials and interfaces
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (35)
Show source-provided references
1. Kang · 2005
2. Densification behavior of Ti-doped polycrystalline alumina in a nitrogen-hydrogen atmosphere10.2320/matertrans.MC200829 ↗
3. Cho · J. Am. Ceram. Soc. · 1997 · 80 · 101310.1111/j.1151-2916.1997.tb02936.x ↗
4. Anisotropic abnormal grain growth in TiO2/SiO2-doped alumina10.1111/j.1151-2916.2000.tb01636.x ↗
5. High-temperature creep resistance in lanthanoid ion-doped polycrystalline Al2O310.1080/095008399177318 ↗
6. Microstructures and electrical properties of TiO2-doped Al2O3 ceramics10.1093/jmicro/dfq037 ↗
7. Grain boundary strengthening in alumina by rare earth impurities10.1126/science.1119839 ↗
8. Electronic band structure of Al2O3, with comparison to AlON and AIN10.1111/j.1151-2916.1990.tb06541.x ↗
9. Atomic-scale imaging of individual dopant atoms in a buried interface10.1038/nmat2486 ↗
10. Direct measurements of grain boundary sliding in yttrium-doped alumina bicrystals10.1063/1.1555690 ↗
11. Anisotropic grain growth in α-Al2O3 with SiO2 and TiO2 additions10.1111/j.1151-2916.2000.tb01642.x ↗
12. Grain boundary electronic structure related to the high-temperature creep resistance in polycrystalline Al2O310.1016/S1359-6454(02)00122-2 ↗
13. Direct measurement of electronic band structures at oxide grain boundaries10.1021/acs.nanolett.9b05298 ↗
14. A density functional study of vacancy formation in grain boundaries of undoped α-alumina10.1016/j.actamat.2014.01.059 ↗
15. Zr segregation and associated Al vacancies in alumina grain boundaries10.2109/jcersj2.119.840 ↗
16. Atomic structure, energetics, and chemical bonding of Y doped Σ13 grain boundaries in α-Al2O310.1080/14786435.2012.733827 ↗
17. Atomic structures and energies of Σ7 symmetrical tilt grain boundaries in alumina bicrystals10.1111/j.1151-2916.2003.tb03343.x ↗
18. Structural and electronic properties of Σ7 grain boundaries in α-Al2O310.1016/j.actamat.2015.07.042 ↗
19. Periodic nanowire array at the crystal interface10.1021/nn4023334 ↗
20. Vibrational and valence aloof beam EELS: a potential tool for nondestructive characterization of nanoparticle surfaces10.1016/j.ultramic.2017.03.011 ↗
21. A limit for bandgap determination and Kramers-Kronig analysis10.1016/j.micron.2006.01.001 ↗
22. Bandgap measurement of thin dielectric films using monochromated STEM-EELS10.1016/j.ultramic.2009.04.005 ↗
23. Spatially resolved electron energy-loss near-edge structure analysis of a near Σ = 11 tilt boundary in sapphire10.1051/mmm:019930040102300 ↗
24. Incoherent imaging of thin specimens using coherently scattered electrons10.1098/rspa.1993.0060 ↗
25. Direct oxygen imaging within a ceramic interface, with some observations upon the dark contrast at the grain boundary10.1016/j.ultramic.2010.12.022 ↗
26. The Band structure of polycrystalline Al2O3 and its influence on transport phenomena10.1111/jace.14149 ↗
27. Impurity-induced structural transformation of a MgO grain boundary10.1103/PhysRevLett.81.3675 ↗
28. Atom-resolved imaging of ordered defect superstructures at individual grain boundaries10.1038/nature10593 ↗
29. Atomically ordered solute segregation behaviour in an oxide grain boundary10.1038/ncomms11079 ↗
30. An NEXAFS investigation of the reduction and reoxidation of TiO2(001)10.1016/S0039-6028(97)00740-1 ↗
31. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides10.1107/S0567739476001551 ↗
32. Aluminum oxide‐titanium oxide solid solution10.1111/j.1151-2916.1963.tb13771.x ↗
33. Formation of titanium-solute clusters in alumina: a first-principles study10.1063/1.1760598 ↗
34. Theoretical study of defect structures in pure and titanium-doped alumina10.1016/j.ssi.2004.01.044 ↗
35. Conducting nanowires in insulating ceramics10.1038/nmat920 ↗