Physics – Condensed Matter – Superconductivity
Scientific paper
2008-05-28
J. Phys. Cond. Matt. Fast Track Commun. 20, 292201 (2008)
Physics
Condensed Matter
Superconductivity
7 pages text + Figs : Comments/suggestions welcome (awana@mail.nplindia.ernet.in)
Scientific paper
We report on the magnetic behavior of oxygen deficient LaFeAsO1-x (x-0.10) compound, prepared by one-step synthesis, which crystallizes in the tetragonal (S.G. P4/nmm) structure at room temperature. Resistivity measurements show a strong anomaly near 150 K, which is ascribed to the spin density wave (SDW) instability. On the other hand, dc magnetization data shows paramagnetic-like features down to 5 K, with an effective moment of 0.83 mB/Fe. 57Fe Mossbauer studies (MS) have been performed at 95 and 200 K. The spectra at both temperatures are composed of two sub-spectra. At 200 K the major one (88%), is almost a singlet, and corresponds to those Fe nuclei, which have two oxygen ions in their close vicinity. The minor one, with a large quadrupole splitting, corresponds to Fe nuclei, which have vacancies in their immediate neighborhood. The spectrum at 95 K, exhibits a broadened magnetic split major (84%) sub-spectrum and a very small magnetic splitting in the minor subspectrum. The relative intensities of the subspectra facilitate in estimating the actual amount of oxygen vacancies in the compound to be 7.0(5)%, instead of the nominal LaFeAsO0.90. These results, when compared with reported 57Fe MS of non-superconducting LaFeAsO and superconducting LaFeAsO0.9F0.1, confirm that the studied LaFeAsO0.93 is a superconductivity-magnetism crossover compound of the newly discovered Fe based superconducting family.
Awana* V. P. S.
Felner Israel
Kishan Hari
Nowik Israel
Vajpayee Arpita
No associations
LandOfFree
57Fe Mossbauer spectroscopy and magnetic measurements of oxygen deficient LaFeAsO does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with 57Fe Mossbauer spectroscopy and magnetic measurements of oxygen deficient LaFeAsO, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 57Fe Mossbauer spectroscopy and magnetic measurements of oxygen deficient LaFeAsO will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-415974