Preparation and electronic properties ofSr2−xLa<

Abstract

K2NiF4-type solid solution system Sr2 La"Rh04 was prepared and the structure and electrical and magnetic properties were investigated.The result of powder x-ray-difFraction analysis shows stretching of the a and b axes and shortening of the e axis with an increase of x. The positive temperature dependence of the resistivity in the range x 0. 15 disappears with an increase of x greater than 0.15. The temperature dependence of the activation energy of carriers suggests two-dimensional variable range hopping-type conduction in the semiconducting range. The localized magnetic moment of the Rh ion is greater than the calculated value based on the low spin state, and the antiferromagnetic interaction among Rh ions decreases with an increase of x. A magnetic anomaly around 60 K observed for Sr2Rh04 diminishes with an increase of x and vanishes at x =0.20. A positive Seebeck coeScient suggests hole conduction in this system and the Fermi energy obtained from the linear temperature dependence of the Seebeck coefticient on T decreases with x, which can be explained from the decrease of holes with the substitution of low spin Rh +(4d ) for Rh +(4d').

Crystal structure and electronic and magnetic properties of the bilayered rhodium oxideSr3Rh2OYamaura1, Huang2, Young3 et al. 2002Phys. Rev. B313360View full textAdd to dashboardCite

“…33 The Seebeck coefficient of Sr 2 RhO 4 , reported previously, was approximately +40µV/K at room temperature and decreases linearly to approach zero upon cooling. 32 The data of all three compounds (Sr 2 RhO 4 , Sr 3 Rh 2 O 7 , and SrRhO 3 ) are qualitatively consistent with the metallic conductivity observed for each, and indicate that the sign of the majority carriers is positive in the metallic conducting state. Among the Seebeck coefficient of the three compounds, it is hard to find a remarkable difference qualitatively and quantitatively, in con- trast to the case of the resistivity data.…”

Single-crystal growth and physical properties of 50% electron-doped rhodate Sr1.5La0.5RhO4

“…A doping dependent metal-insulator transition and a complex magnetic behavior that may be connected to the structural changes have been observed 9 . Furthermore, a quasi-twodimensional Fermi liquid state has been reported in floating zone grown single crystals of the undoped parent compound Sr 2 RhO 4 10,11 .…”

“…However, the rhodium oxides that also crystallize in the K 2 NiF 4 -type structure were less investigated so far. Besides of a comparative study of Sr 2 RhO 4 single crystals isotypic with Sr 2 RuO 4 mainly polycrystalline Sr 2−x La x RhO 4 samples were studied over a wider doping range x = 0 ∼ 1.0 [9][10][11] . Regarding the recent observations of charge order and nano phase separation in the 3d cobaltate system La 2−x Sr x CoO 4 [12][13][14][15] also the availability of single crystals of the 4d Rhodium analogue with hole-doping levels away from the end member Sr 2 RhO 4 and, especially, around 50% electron doping (Sr 1.5 La 0.5 RhO 4 ), would be of interest for future studies of the charge correlations.…”

Thermoelectric Properties of B-Site Substituted LaRhO3

“…Many reports of Rh perovskite [10][11][12][13][14][15] have been made, however the thermoelectric properties of these compounds have not been extensively studied. Bi-Ba-Rh-O, Sr-Rh-O, and Cu-Rh-O have been extensively studied, as they are expected to have similar electronic states to Co oxides.…”