The chemical control of colossal magnetoresistance (CMR) in the new two-dimensional La-1.2(Sr1.8-xCax)Mn2O7 system
Journal
International Journal of Inorganic Materials
Journal Volume
1
Journal Issue
1
Pages
61-65
Date Issued
1999
Author(s)
Abstract
The magnetic and electrical properties of the colossal magnetoresistance (CMR) La1.2(Sr1.8-xCax)Mn2O7 materials have been investigated. Based on the chemical titration method, the valence of Mn was determined to be 3.39±0.04 for all measured La1.2(Sr1.8-xCax)Mn2O7. The magnetoresistance ratio [ρ(0)/ρ(H)] was efficiently increased from ~192% (135 K, 1.5 T) for x=0 to 208% (102 K, 1.5 T) for x=0.4 in La1.2(Sr1.8-xCax)Mn2O7. Moreover, the Curie temperature (Tc) decreased with increasing x and was strongly dependent on the apical bond lengths of Mn-O(2). © Elsevier Science Ltd.
Type
journal article