Phase transitions and iron-ordered moment form factor in LaFeAsO
| Title | Phase transitions and iron-ordered moment form factor in LaFeAsO |
| Publication Type | Journal Article |
| Year of Publication | 2010 |
| Authors | Li HF, Tian W, Yan JQ, Zarestky JL, McCallum RW, Lograsso TA, Vaknin D |
| Journal Title | Physical Review B |
| Volume | 82 |
| Pages | 064409 |
| Date Published | 8/09 |
| ISBN Number | 1098-0121 |
| Accession Number | ISI:000280758300004 |
| Keywords | superconductivity |
| Abstract | Elastic neutron-scattering studies of single-crystal LaFeAsO reveal that upon cooling, an onset of the tetragonal (T)-to-orthorhombic (O) structural transition occurs at T-S approximate to 156 K, and it exhibits a sharp transition at T-P approximate to 148 K. We argue that in the temperature range T-S to T-P, T and O structures may dynamically coexist possibly due to nematic spin correlations recently proposed for the iron pnictides, and we attribute T-P to the formation of long-range O domains from the finite local precursors. The antiferromagnetic structure emerges at T-N approximate to 140 K, with the iron moment direction along the O a axis. We extract the iron magnetic form factor and use the tabulated < j(0)> of Fe, Fe2+, and Fe3+ to obtain a magnetic moment size of similar to 0.8 mu B at 9.5 K. |
| URL | <Go to ISI>://000280758300004 |
| DOI | 10.1103/Physrevb.82.064409 |
