Influence of Nd Substitution by La in Nd0.7Sr0.3MnO3 on Structural and Transport Properties for Sensing Applications. (21st February 2013)

• Record Type: Journal Article
• Authors: Vadnala, Sudarshan; Asthana, Saket; Pal, Prem; Srinath, S.
• Other Names: Baranauskas V. Academic Editor.; Ralchenko V. Academic Editor.
• Is Part Of: ISRN materials science. Volume 2013(2013)
• Publication Date: 2013-02-21
• Subjects: Materials science -- Periodicals; Materials science; Periodicals; 620.11
• DOI: 10.1155/2013/728195
• Languages: English
• ISSNs: 2090-6080

Abstract

Abstract : The structural and transport properties of Nd 0.7 - x La x Sr 0.3 MnO 3 manganites with x = 0, 0.1, and 0.2 prepared by solid state reaction route are studied. These compounds are found to be crystallized in orthorhombic structural form. A shift in the metal-semiconductor/insulator transition temperature (T MI ) towards room temperature (289 K) with the substitution of Nd by La, as the value of x is varied in the sequence (0, 0.1, and 0.2), has been provided. The shift in the T MI, from 239 K (for x = 0 ) to near the room temperature 289 K (for x = 0.2 ), is attributed to the fact that the average radius 〈 r A 〉 of site-A increases with the percentage of La. The maximum temperature coefficients of resistance (TCR) of Nd 0.7 - x La x Sr 0 .3 MnO 3 (x = 0.1 and 0.2) are found to be higher compared to its parent compound Nd 0 .7 Sr 0 .3 MnO 3 which is almost independent of 〈 r A 〉 . The electrical resistivity of the experimental results is explored by various theoretical models below and above T MI . An appropriate enlightenment for the observed behavior is discussed in detail.