TY  - JOUR
AU  - Ribić, Vesna
AU  - Recnik, Aleksander
AU  - Drazic, Goran
AU  - Podlogar, Matejka
AU  - Branković, Zorica
AU  - Branković, Goran
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1471
AB  - In our recent study (Ribie et al. 2020) we reported the structure of inversion boundaries (IBs) in Sb2O3 -doped ZnO. Here, we focus on IBs that form in SnO2-doped ZnO. Using atomic resolution scanning transmission electron microscopy (STEM) methods we confirm that in SnO2-doped ZnO the IBs form in head-to-head configuration, where ZnO4 tetrahedra in both ZnO domains point towards the IB plane composed of a close packed layer of octahedrally coordinated Sn and Zn atoms. The in-plane composition is driven by the local charge balance, following Pauling's principle of electroneutrality for ionic crystals, according to which the average oxidation state of cations is 3+. To satisfy this condition, the cation ratio in the IB-layer is Sn4+ : Zn2+ =1:1. This was confirmed by concentric electron probe analysis employing energy dispersive spectroscopy (EDS) showing that Sn atoms occupy 0.504 +/- 0.039 of the IB layer, while the rest of the octahedral sites are occupied by Zn. IBs in SnO2-doped ZnO occur in the lowest energy, IB3 translation state with the cation sublattice expansion of Delta IB(zn-zn) of +91 pm with corresponding O-sublattice contraction Delta IB(O-O) of -46 pm. Based on quantitative HRTEM and HAADF-STEM analysis of in-plane ordering of Sn and Zn atoms, we identified two types of short-range distributions, (i) zigzag and (ii) stripe. Our density functional theory (DFT) calculations showed that the energy difference between the two arrangements is small (similar to 6 meV) giving rise to their alternation within the octahedral IB layer. As a result, cation ordering intermittently changes its type and the direction to maximize intrinsic entropy of the IB layer driven by the in-plane electroneutrality and 6-fold symmetry restrictions. A long-range in-plane disorder, as shown by our work would enhance quantum well effect to phonon scattering, while Zn2+ located in the IB octahedral sites, would modify the the bandgap, and enhance the in-plane conductivity and concentration of carriers.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - TEM and DFT Study of Basal-plane Inversion Boundaries in SnO2-doped ZnO
EP  - 252
IS  - 2
SP  - 237
VL  - 53
DO  - 10.2298/SOS2102237R
ER  - 

@article{
author = "Ribić, Vesna and Recnik, Aleksander and Drazic, Goran and Podlogar, Matejka and Branković, Zorica and Branković, Goran",
year = "2021",
abstract = "In our recent study (Ribie et al. 2020) we reported the structure of inversion boundaries (IBs) in Sb2O3 -doped ZnO. Here, we focus on IBs that form in SnO2-doped ZnO. Using atomic resolution scanning transmission electron microscopy (STEM) methods we confirm that in SnO2-doped ZnO the IBs form in head-to-head configuration, where ZnO4 tetrahedra in both ZnO domains point towards the IB plane composed of a close packed layer of octahedrally coordinated Sn and Zn atoms. The in-plane composition is driven by the local charge balance, following Pauling's principle of electroneutrality for ionic crystals, according to which the average oxidation state of cations is 3+. To satisfy this condition, the cation ratio in the IB-layer is Sn4+ : Zn2+ =1:1. This was confirmed by concentric electron probe analysis employing energy dispersive spectroscopy (EDS) showing that Sn atoms occupy 0.504 +/- 0.039 of the IB layer, while the rest of the octahedral sites are occupied by Zn. IBs in SnO2-doped ZnO occur in the lowest energy, IB3 translation state with the cation sublattice expansion of Delta IB(zn-zn) of +91 pm with corresponding O-sublattice contraction Delta IB(O-O) of -46 pm. Based on quantitative HRTEM and HAADF-STEM analysis of in-plane ordering of Sn and Zn atoms, we identified two types of short-range distributions, (i) zigzag and (ii) stripe. Our density functional theory (DFT) calculations showed that the energy difference between the two arrangements is small (similar to 6 meV) giving rise to their alternation within the octahedral IB layer. As a result, cation ordering intermittently changes its type and the direction to maximize intrinsic entropy of the IB layer driven by the in-plane electroneutrality and 6-fold symmetry restrictions. A long-range in-plane disorder, as shown by our work would enhance quantum well effect to phonon scattering, while Zn2+ located in the IB octahedral sites, would modify the the bandgap, and enhance the in-plane conductivity and concentration of carriers.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "TEM and DFT Study of Basal-plane Inversion Boundaries in SnO2-doped ZnO",
pages = "252-237",
number = "2",
volume = "53",
doi = "10.2298/SOS2102237R"
}

Ribić, V., Recnik, A., Drazic, G., Podlogar, M., Branković, Z.,& Branković, G.. (2021). TEM and DFT Study of Basal-plane Inversion Boundaries in SnO2-doped ZnO. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 53(2), 237-252.
https://doi.org/10.2298/SOS2102237R

Ribić V, Recnik A, Drazic G, Podlogar M, Branković Z, Branković G. TEM and DFT Study of Basal-plane Inversion Boundaries in SnO2-doped ZnO. in Science of Sintering. 2021;53(2):237-252.
doi:10.2298/SOS2102237R .

Ribić, Vesna, Recnik, Aleksander, Drazic, Goran, Podlogar, Matejka, Branković, Zorica, Branković, Goran, "TEM and DFT Study of Basal-plane Inversion Boundaries in SnO2-doped ZnO" in Science of Sintering, 53, no. 2 (2021):237-252,
https://doi.org/10.2298/SOS2102237R . .