New mixed valence iron oxides (Pb,A)Sr4Fe2O9-delta (A=Cd, Hg) with the 0201-1201 intergrowth type structure

被引：4

作者：

Nguyen, N

Daniel, P

Groult, D

Raveau, B

Greneche, JM

机构：

[1] UNIV CAEN,ISMRA,URA 1318 CNRS,LAB CRISMAT,F-14050 CAEN,FRANCE

[2] UNIV MAINE,URA 807 CNRS,LAB PHYS ETAT CONDENSE,F-72017 LE MANS,FRANCE

来源：

MATERIALS CHEMISTRY AND PHYSICS | 1996年 / 45卷 / 01期

关键词：

crystal structure; iron oxides; Mossbauer spectroscopy;

D O I：

10.1016/0254-0584(96)80044-7

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

New mixed valence iron oxides (Pb(1-x)A(x))Sr4Fe2O9-delta have been isolated for the composition range 0 less than or equal to x less than or equal to 0.5 and A = Cd, Hg. Powder X-ray diffraction (XRD) refinements and chemical analysis data demonstrated that both compounds exhibit a significant non-stoichiometry in intermediate rock salt-type [(Pb, A)O](infinity) layers. Mossbauer spectroscopy measurements performed at 4.2 and 300 K showed the existence of several iron sites which have been assigned to individual high spin Fe(III) and to a temperature-dependent intermediate valence state Fe(IV - Delta) due to electron hopping between iron sites.

引用

页码：33 / 38

页数：6

共 18 条

[11] THE SUPERCONDUCTORS (TL, PB)SR2CACU2O7 AND (TL, PB)SR2CA2CU3O9 - NEUTRON POWDER DIFFRACTION, HIGH-RESOLUTION ELECTRON-MICROSCOPY AND X-RAY ABSORPTION STUDIES [J].