Carrier filtering effect for enhanced thermopower in a body-centered tetragonal ruthenate
arXiv:2309.05313 · doi:10.1103/PhysRevMaterials.7.125401
Abstract
Charged carriers in solids diffuse from hot to cold sides under temperature gradient to induce the thermoelectric voltage. Carrier filtering effect, which only passes either electrons or holes for the conduction process, is an efficient method to enhance such voltage, although it is challenging to experimentally realize it especially in conventional metals with weak energy dependence of the density of states near the Fermi level. Here we measure the in-plane and out-of-plane thermopower of the layered perovskite SrRuO single crystals above room temperature, and find that the out-of-plane thermopower is largely enhanced with increasing temperature, while the in-plane one seems to remain a temperature-independent constant value which is expected from the Heikes formula. The observed large out-of-plane thermopower may originate from the recently proposed intriguing hole filtering effect in the body-centered tetragonal system, in which the carrier hopping through the centered atom is essential. Thus, the present carrier filtering effect may be a universal property to be applicable in various materials belonging to such crystal system.
7 pages, 5 figures. Accepted for publication in Phys. Rev. Materials
References in corpus (19)
- Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
- Advanced capabilities for materials modelling with Quantum ESPRESSO
- BoltzTraP. A code for calculating band-structure dependent quantities
- Quantum ESPRESSO toward the exascale
- Strong electronic correlations from Hund's coupling
- Theory of universal incoherent metallic transport
- Chiral P-Wave Order in Sr_2RuO_4
- Transport and magnetic properties of GdBaCo_{2}O_{5+x} single crystals: A cobalt oxide with square-lattice CoO_2 planes over a wide range of electron and hole doping
- "Pudding mold" band drives large thermopower in NaCoO
- Strong spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4
- Spin blockade, orbital occupation and charge ordering in La_(1.5)Sr_(0.5)CoO4
- Thermoelectrics: from Longitudinal to Transverse
- Origin of the large thermoelectric power in oxygen-variable RBaCo_{2}O_{5+x} (R=Gd, Nd)
- Band-dependent normal-state coherence in SrRuO: Evidence from Nernst effect and thermopower measurements
- Crossover from itinerant to localized states in the thermoelectric oxide [CaCoO][CoO]
- Enhanced Seebeck coefficient through the magnetic fluctuations in SrRuO ( Co, Mn)
- Prominent electron-hole asymmetry in thermoelectric transport of LaCoO
- Anomalous scaling law for thermoelectric transport of 2D-confined electrons in an organic molecular system
- Anisotropic Seebeck coefficient of in the incoherent regime