Peculiarities of Ferroelectric Phase Transition in (Ba, Sr) TiO3 Heteroepitaxial Films Obtained by HF Cathode Sputtering

1989 ◽  
Vol 114 (2) ◽  
pp. 559-566 ◽  
Author(s):  
I. N. Zakharchenko ◽  
E. S. Nikitin ◽  
V. M. Mukhortov ◽  
Yu. I. Golovko ◽  
M. G. Radchenko ◽  
...  
Keyword(s):  
Phase Transition ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Cathode Sputtering

scholarly journals The origin of the lattice thermal conductivity enhancement at the ferroelectric phase transition in GeTe

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Đorđe Dangić ◽  
Olle Hellman ◽  
Stephen Fahy ◽  
Ivana Savić
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Phase Transitions ◽  
Thermoelectric Materials ◽  
Ferroelectric Phase Transition ◽  
Lattice Thermal Conductivity ◽  
Ferroelectric Phase ◽  
Structural Phase ◽  
High Symmetry ◽  
Structural Phase Transitions

AbstractThe proximity to structural phase transitions in IV-VI thermoelectric materials is one of the main reasons for their large phonon anharmonicity and intrinsically low lattice thermal conductivity κ. However, the κ of GeTe increases at the ferroelectric phase transition near 700 K. Using first-principles calculations with the temperature dependent effective potential method, we show that this rise in κ is the consequence of negative thermal expansion in the rhombohedral phase and increase in the phonon lifetimes in the high-symmetry phase. Strong anharmonicity near the phase transition induces non-Lorentzian shapes of the phonon power spectra. To account for these effects, we implement a method of calculating κ based on the Green-Kubo approach and find that the Boltzmann transport equation underestimates κ near the phase transition. Our findings elucidate the influence of structural phase transitions on κ and provide guidance for design of better thermoelectric materials.

Ferroelectric phase transition in Pb(Cd1/2Mo1/2)O3 ceramics

2001 ◽  
Vol 51 (4) ◽  
pp. 301-306 ◽  
Author(s):  
Ratnakar Palai ◽  
R.N.P. Choudhary ◽  
Seema Sharma
Keyword(s):  
Phase Transition ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase
Sign in / Sign up

Export Citation Format

Share Document