TY  - JOUR
AU  - Li, H.-F.
AU  - Su, Y.
AU  - Persson, J.
AU  - Meuffels, P.
AU  - Walter, J. M.
AU  - Skowronek, R.
AU  - Brückel, T.
TI  - Neutron-diffraction study of structural transition and magnetic order in orthorhombic and rhombohedral La7/8Sr1/8Mn1-gammaO3+delta
JO  - Journal of physics / Condensed matter
VL  - 19
SN  - 0953-8984
CY  - Bristol
PB  - IOP Publ.
M1  - PreJuSER-56407
SP  - 176226-1 -176226-12
PY  - 2007
N1  - Record converted from VDB: 12.11.2012
AB  - We report on a systematic neutron powder diffraction (NPD) study of polycrystalline La(7/8)Sr(1/8)Mn(1-γ)O(3+δ) compounds. We investigated the structural and magnetic phases and transitions in the temperature range between 10 and 900 K for two different samples: an Ar-annealed sample with an orthorhombic Pbnm (Z = 4; O) structure at room temperature and an air-sintered sample with a rhombohedral [Formula: see text] (Z = 2;R) structure at room temperature. At higher temperatures, above 400 K, both samples exhibit a rhombohedral structure. For the Ar-annealed sample, a Jahn-Teller (JT) transition occurs in the orthorhombic phase at about 298 K with very large variations in the Mn-O2' and Mn-O2 bond lengths and Mn-O1-Mn bond angle on cooling from 298 to 180 K. For this sample the ferromagnetic moment at 10 K in the magnetic space group Pb'n'm amounts to 3.22(5) μ(B)/Mn. In contrast, the air-sintered sample undergoes on cooling a structural transition from rhombohedral (R) to orthorhombic (O) with a mixed phase of nearly equal R and O repartition at 120 K. Ferromagnetic order develops in this sample at about 240 K with a low-temperature moment of 3.35(4) μ(B)/Mn at 10 K. The coherent JT distortion in its orthorhombic phase occurs below some 170 K. In addition, we have determined the coherent JT distortion parameter Δ, the tolerance factor t and the one-electron bandwidth W of the e(g)-band.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:21690971
UR  - <Go to ISI:>//WOS:000246556400038
DO  - DOI:10.1088/0953-8984/19/17/176226
UR  - https://juser.fz-juelich.de/record/56407
ER  -