Structure And Magnetotransport Properties Of The Layered Manganites REl.2Srl.8Mn,07(R E = La, Pr, Nd)

Content Provider	Indian Institute of Science (IISc)
Author	Seshadri, R. A. M. Martin, Christine Maignan, Antoine Hervieu, Maryvonne Raveau, Bernard Rao, C. N. R.
Copyright Year	1996
Abstract	We have examined the magnetotransport properties and the structure, by Rietveld refinement of powder X-ray data, of the phases RE(1.2)Sr(1.8)Mn(2)O(7) (RE = La, Pr, Nd). We find that on cooling, La1.2Sr1.8Mn2O7 undergoes a transition to a nearly perfect ferromagnet with 90% magnetization at 1.45 T, as reported by earlier workers, but the Pr and Nd phases show only a small magnetization that grows gradually as the temperature is decreased. There seems to be significant correlation between electrical transport and the Jahn-Teller elongation of the apical Mn-O bonds in these systems. The elongation of the apical Mn-O bonds forces the nine-coordinate rock-salt site to be occupied preferentially by the smaller rare-earth-metal cations. This preferential occupation is reliably obtained from the X-ray refinement. All three title phases show a magnetoresistance ratio of about 4(corresponding to a magnetoresistance, [R(0)-R(H)] R(0), of about 75%) at a field of 7 T and temperatures around 100 K.
File Format	PDF
Journal	PeerReviewed
Language	English
Publisher	Royal Society of Chemistry
Publisher Date	1996-09-01
Access Restriction	Authorized
Subject Keyword	Solid State & Structural Chemistry Unit
Content Type	Text
Resource Type	Article