Journal
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
Volume 245, Issue 11, Pages 2363-2368Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/pssb.200844248
Keywords
-
Categories
Ask authors/readers for more resources
This review provides the origin of the unusually large thermoelectric Seebeck coefficient |S| of a two-dimensional electron gas confined within a unit cell layer thickness (similar to 0.4 nm) of a SrTi0.8Nb0.2O3 layer of artificial superlattices of SrTiO3/SrTi0.8Nb0.2O3 [H. Ohta et al., Nature Mater 6, 129, (2007)]. The |S|(2D) values of the [(SrTiO3)(17)/SrTi0.8Nb0.2O3)(y)](20) superlattice increase proportional y(0.5), and reach 290 mu VK-1 (y = 1) at room temperature, which is similar to 5 times larger than that of the SrTi0.8Nb0.2O3 bulk (|S|(3D) = 61 mu VK-1) proving that the density of states in the ground state of SrTiO3 increases in inverse proportion to y. The critical barrier thickness for quantum electron confinement is also clarified to be 6.25 nm (16 unit cells of SrTiO3). Significant structural changes are not observed in the superlattice after annealing at 900 K in a vacuum. The value of |S|(2D) of the superlattice gradually increases with temperature and reaches 450 mu VK-1 at 900 K, which is similar to 3 times larger than that of bulk SrTi0.8Nb0.2O3. These observations provide clear evidence than the [(SrTiO3)(17)/SrTi0.8Nb0.2O3)](20) superlattice is stable and exhibits a giant |S| even at high temperature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available