Effect of Ga-substitution for Fe sites of delafossite CuFe1-xGaxO2 (X = 0.0, 0.1, 0.3, 0.5) on thermal conductivity

Hongaromkij, Yuttana; Rudradawong, Chalermpol; Ruttanapun, Chesta

doi:10.1007/s10854-016-4583-5

Effect of Ga-substitution for Fe sites of delafossite CuFe1-xGaxO2 (X = 0.0, 0.1, 0.3, 0.5) on thermal conductivity

Author(s)

Hongaromkij, Yuttana

Rudradawong, Chalermpol

Ruttanapun, Chesta

Date Issued

March 5, 2016

Type

Article

DOI

10.1007/s10854-016-4583-5

Abstract

This work aimed to study the effect of the Ga³⁺-substitution of Fe³⁺ sites in CuFeO2 delafossite on its thermal conductivity. CuFe1-xGaxO2 (x = 0, 0.1, 0.3, and 0.5) samples were synthesized and their phase structure and ionic composition were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The thermal conductivity of the samples was measured at a high temperature range of 298-573 K. The XRD results confirmed that the samples were pure phase delafossite with hexagonal structure space group: R3m while the EDX results showed composition atomic percent of Ga 100% of x = 0.1, 93% of x = 0.3 and 90% of x = 0.5 and the XPS results revealed Cu¹⁺ and Cu²⁺, Fe²⁺ and Fe³⁺, and Ga³⁺ ion states in the structure. The Ga-substitution decreased the thermal conductivity of the samples below that of nondoped CuFeO2. The high substitution sample (x = 0.5) exhibited the lowest thermal conductivity, 2.5 W/mK at 573 K. Ga substitution into Fe sites affected the lattice thermal conductivity partly through phonon scattering processes arising from mass difference and lattice strain.

Citation

Journal of Materials Science Materials in Electronics, 27(6), 6438-6444, 2016