title: Nanostructured YbAgCu4 for potentially cryogenic thermoelectric cooling.
abstract: We have studied the thermoelectric properties of nanostructured YbAgCu4 materials. A high power factor of ∼131 μW cm(-1) K(-2) has been obtained at 22 K for nanostructured samples prepared by ball milling the arc melted ingot into nanopowder and hot pressing the nanopowder. The implementation of nanostructuring method decreased the thermal conductivity at 42 K by 30-50% through boundary scattering comparing with the previously reported value of polycrystalline YbAgCu4. A peak dimensionless thermoelectric figure-of-merit, ZT, of 0.11 has been achieved at 42 K, which may find potential applications for cryogenic cooling below 77 K. The nanostructuring approach can be extended to other heavy Fermion materials to achieve high power factor and low thermal conductivity and ultimately higher ZT.
authors: Department of Physics and TcSUH, University of Houston , Houston, Texas 77204, United States.
authors: Machhindra
authors: M
authors: Koirala
authors: Hui
authors: H
authors: Wang
authors: Mani
authors: M
authors: Pokharel
authors: Yucheng
authors: Y
authors: Lan
authors: Chuanfei
authors: C
authors: Guo
authors: Cyril
authors: C
authors: Opeil
authors: Zhifeng
authors: Z
authors: Ren
keywords: Kondo lattice; Thermoelectric; YbAgCu4; boundary scattering; heavy Fermions