Thermoelectric transport properties in 3D Dirac semimetal Cd₃As₂

Abstract

Thermoelectric transport properties, namely, electrical conductivity, electronic thermal conductivity, and diffusion thermopower are theoretically investigated in 3D Dirac semimetal Cd 3 As 2 . We employ Boltzmann transport formalism and consider the electron scattering by charged impurities, short-range disorder, acoustic phonons, and optical phonons. The Boltzmann transport equation is solved using the Ritz iteration technique to obtain the firstorder perturbation distribution function for the interaction of electrons with inelastic polar optical phonons scattering. The numerical results are presented in the temperature range 2-300 K with the electron concentration in the range (0.1-10) × 10 18 cm −3 . It is found that, at low temperature < ~70 K transport coefficients are dominated by charged impurity scattering and at higher temperature the phonon scattering is found to be dominant. The validity of Wiedemann-Franz law is examined. Recently observed experimental results are explained by our theory.

Strong Anisotropy and Bipolar Conduction-Dominated Thermoelectric Transport Properties in the Polycrystalline Topological Phase of ZrTe5

“…The electronic transport characteristics of single-crystal ZrTe 5 are closely related to doping and differ from traditional TE materials and typical topological semimetals (such as NbP − and Cd 3 As 2 − ). N-type doped single-crystal ZrTe 5 showed an anomalous resistivity peak and a change in sign of the Seebeck coefficient with increasing temperature, while p-type samples exhibited characteristics similar to narrow-band gap TE materials, as shown in Figure b. ,, The electronic transport characteristics of ZrTe 5 are closely related to the above-mentioned band structure transition with temperature and the temperature-induced Lifshitz transition.…”

Lattice thermal conduction in cadmium arsenide

“…We have performed numerical calculations of κ L (T ) using Eqs. ( 3)-( 13), for characteristic parameters of Cd 3 As 2 : [17,22,33] a = 3.189 Å, c = 5.185 Å, v L = 3500 ms −1 , and v T = 2160 ms −1 . The Debye temperature depends on the phonon spectrum and is known to be different for the three acoustic modes.…”

“…So far, there have been only a few reports [20][21][22] with regard to theoretical investigations of thermal transport properties of Cd 3 As 2 . Lundgren et al, [21] in their analytical study of the thermoelectric properties of Weyl and Dirac semimetals, used a semiclassical Boltzmann approach to investigate the effect of various electron relaxation processes due to charged impurities, short-range disorder and electron-electron interactions on the electronic contribution to TC.…”

“…They ignored the κ L contribution from phonons to the TC. Recently, solving the Boltzmann transport equation using an iteration technique, Amarnath et al [22] studied the temperature dependence of κ e considering contributions from various electron scattering mechanisms. Their attempt to explain the TC data of Wang et al, [10] Zhang et al [11] and Pariari et al, [12] in terms of only the electronic contribution could obtain agreement only for T >∼ 100 K.…”

Знакопеременное Магнетосопротивление И Температурная Зависимость Электропроводности Монокристаллов Твердых Растворов Арсенида Кадмия

“…Введение. Ранее было установлено, что (Cd 3 As 2 ) является трехмерным полуметаллом Дирака[1,3], который обладает чрезвычайно высокой подвижностью, особыми транспортными свойствами, такими как большое магнетосопротивление в поперечных магнитных полях, что может иметь значение для практического применения[10]. В последние годы широко исследуется эффект отрицательного магнетосопротивления в топологических материалах и механизмы его возникновения[4].…”