Research output: Contribution to journal › Article › peer-review
First-principles modeling of hafnia-based nanotubes. / Evarestov, Robert A.; Bandura, Andrei V.; Porsev, Vitaly V.; Kovalenko, Alexey V.
In: Journal of Computational Chemistry, Vol. 38, No. 24, 15.09.2017, p. 2088-2099.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - First-principles modeling of hafnia-based nanotubes
AU - Evarestov, Robert A.
AU - Bandura, Andrei V.
AU - Porsev, Vitaly V.
AU - Kovalenko, Alexey V.
PY - 2017/9/15
Y1 - 2017/9/15
N2 - Hybrid density functional theory calculations were performed for the first time on structure, stability, phonon frequencies, and thermodynamic functions of hafnia-based single-wall nanotubes. The nanotubes were rolled up from the thin free layers of cubic and tetragonal phases of HfO2. It was shown that the most stable HfO2 single-wall nanotubes can be obtained from hexagonal (111) layer of the cubic phase. Phonon frequencies have been calculated for different HfO2 nanolayers and nanotubes to prove the local stability and to find the thermal contributions to their thermodynamic functions. The role of phonons in stability of nanotubes seems to be negligible for the internal energy and noticeable for the Helmholtz free energy. Zone folding approach has been applied to estimate the connection between phonon modes of the layer and nanotubes and to approximate the nanotube thermodynamic properties. It is found that the zone-folding approximation is sufficiently accurate for heat capacity, but less accurate for entropy. The comparison has been done between the properties of TiO2, ZrO2, and HfO2.
AB - Hybrid density functional theory calculations were performed for the first time on structure, stability, phonon frequencies, and thermodynamic functions of hafnia-based single-wall nanotubes. The nanotubes were rolled up from the thin free layers of cubic and tetragonal phases of HfO2. It was shown that the most stable HfO2 single-wall nanotubes can be obtained from hexagonal (111) layer of the cubic phase. Phonon frequencies have been calculated for different HfO2 nanolayers and nanotubes to prove the local stability and to find the thermal contributions to their thermodynamic functions. The role of phonons in stability of nanotubes seems to be negligible for the internal energy and noticeable for the Helmholtz free energy. Zone folding approach has been applied to estimate the connection between phonon modes of the layer and nanotubes and to approximate the nanotube thermodynamic properties. It is found that the zone-folding approximation is sufficiently accurate for heat capacity, but less accurate for entropy. The comparison has been done between the properties of TiO2, ZrO2, and HfO2.
KW - hafnia
KW - nanolayers
KW - phonon frequencies
KW - strain energy
KW - thermodynamic properties
KW - zone folding
UR - http://www.scopus.com/inward/record.url?scp=85020717639&partnerID=8YFLogxK
U2 - 10.1002/jcc.24849
DO - 10.1002/jcc.24849
M3 - Article
AN - SCOPUS:85020717639
VL - 38
SP - 2088
EP - 2099
JO - Journal of Computational Chemistry
JF - Journal of Computational Chemistry
SN - 0192-8651
IS - 24
ER -
ID: 9307714