Single valence and structural order in the colossal-magnetoresistant pyrochlore Tl2Mn2O7

被引：29

作者：

Kwei, GH

Booth, CH

Bridges, F

Subramanian, MA

机构：

[1] UNIV CALIF SANTA CRUZ, DEPT PHYS, SANTA CRUZ, CA 95064 USA

[2] DUPONT CO INC, CENT RES & DEV, EXPT STN, WILMINGTON, DE 19880 USA

来源：

PHYSICAL REVIEW B | 1997年 / 55卷 / 02期

关键词：

D O I：

10.1103/PhysRevB.55.R688

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Without Mn3+/Mn4+ mixed-valence or Jahn-Teller distortions in the MnO6 octahedra, the origin of colossal magnetoresistance (CMR) in the pyrochlore Tl2Mn2O7 is thought to arise instead from superexchange with large incoherent scattering near the ferromagnetic transition. Using x-ray-absorption spectroscopy, we have shown that the electronic state of T1 is nearly identical to that in Tl2O3, indicating doping into the T1 6s bands, that there is no appreciable Mn mixed valence, and that the MnO6 octahedra are well ordered. This further supports the proposed mechanism for CMR in Tl2Mn2O7 based on our earlier structural studies.

引用

页码：R688 / R691

页数：4

共 19 条

[11] FURTHER EVIDENCE FOR TL3+ IN TL-BASED SUPERCONDUCTORS FROM IMPROVED BOND STRENGTH PARAMETERS INVOLVING NEW STRUCTURAL DATA OF CUBIC TL2O3
OTTO, HH
BALTRUSCH, R
BRANDT, HJ
[J]. PHYSICA C, 1993, 215 (1-2): : 205 - 208
[12] Lattice effects in the colossal-magnetoresistance manganites
Roder, H
Zang, J
Bishop, AR
[J]. PHYSICAL REVIEW LETTERS, 1996, 76 (08) : 1356 - 1359
[13] REVISED EFFECTIVE IONIC-RADII AND SYSTEMATIC STUDIES OF INTERATOMIC DISTANCES IN HALIDES AND CHALCOGENIDES
SHANNON, RD
[J]. ACTA CRYSTALLOGRAPHICA SECTION A, 1976, 32 (SEP1): : 751 - 767
[14] Giant magnetoresistance in Tl2Mn2O7 with the pyrochlore structure
Shimakawa, Y
Kubo, Y
Manako, T
[J]. NATURE, 1996, 379 (6560) : 53 - 55
[15] SLEIGHT AW, 1988, P RA WELCH F C VALEN, V32, P123
[16] Colossal magnetoresistance without Mn3+/Mn4+ double exchange in the stoichiometric pyrochlore Tl2Mn2O7
Subramanian, MA
Toby, BH
Ramirez, AP
Marshall, WJ
Sleight, AW
Kwei, GH
[J]. SCIENCE, 1996, 273 (5271) : 81 - 84
[17] GIANT NEGATIVE MAGNETORESISTANCE IN PEROVSKITELIKE LA2/3BA1/3MNOX FERROMAGNETIC-FILMS
VONHELMOLT, R
WECKER, J
HOLZAPFEL, B
SCHULTZ, L
SAMWER, K
[J]. PHYSICAL REVIEW LETTERS, 1993, 71 (14) : 2331 - 2333
[18] MULTIPLE-SCATTERING CALCULATIONS OF X-RAY-ABSORPTION SPECTRA
ZABINSKY, SI
REHR, JJ
ANKUDINOV, A
ALBERS, RC
ELLER, MJ
[J]. PHYSICAL REVIEW B, 1995, 52 (04): : 2995 - 3009
[19] INTERACTION BETWEEN THE D-SHELLS IN THE TRANSITION METALS .2. FERROMAGNETIC COMPOUNDS OF MANGANESE WITH PEROVSKITE STRUCTURE
ZENER, C
[J]. PHYSICAL REVIEW, 1951, 82 (03): : 403 - 405

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