Electric-Field-Controlled Thermal Switch in Ferroelectric Materials Using First-Principles Calculations and Domain-Wall Engineering

Reduction of thermal conductivity in ferroelectric SrTiO3 thin films

“…Note also that Eq. (2) is valid in the diffusive regime, i.e., when the phonon mean free path λ is smaller than the value of φ. First-principles calculations of the cumulative thermal conductivity predicted a very large contribution from phonons with λ < 10 nm, of about 60%-70% at room temperature [37,38]. Therefore, the use of Eq.…”

“…3, as explained in the text. The highlighted area marks the mean free path of the phonons that contribute the most to the thermal conductivity at room temperature [37,38]. without thermal resistance inside the different regions, κ 0 → ∞, and Eq.…”

Phonon thermal transport properties of GaN with symmetry-breaking and lattice deformation induced by the electric field

“…However, the effects of electric fields on lattice thermal transport in GaN are still unclear, which is critical for thermal management in GaN-based transistors [4]. Besides, applying external electric field is an effective way to tune electrical and thermal transport properties of dielectric materials [9][10][11][12][13][14][15]. Theoretically, the response of lattice to finite homogenous electric field can be classified as three parts [16,17]: (i) response of electron wave function (density distribution), which can be represented by Born effective charges and dielectric function, as well as interatomic force constants in phonon calculations; (ii) changes of atomic coordinates; and (iii) lattice strain, including electronic part and lattice part.…”

“…In cases where response of electronic part can be ignored, this method has been applied well to study the lattice thermal transport accompanied with structure phase transition. As a result, it is now feasible to investigate the thermal transport properties of three-dimensional periodic solids [12][13][14]28].…”

Strain-Engineered Ferroelastic Structures in PbTiO3 Films and Their Control by Electric Fields

“…Our findings pave the way for the design of non-volatile ferroelastic structures that can be harnessed in reconfigurable nanoscale electronic circuitry, 9 in electromechanical applications, 5,29 or even in ferroelectricbased phononic devices. [34][35][36][37]…”