The effects of structural, electrical and magnetic properties with the isovalent chemical substitution of Ca2+ into the Sr2+ sites in La1.2(Sr1.8-xCax)Mn2O7 (x = 0-0.8) are investigated. The highest magnetoresistance ratio [ρ(0)/ρ(H)] of 208% (H = 1.5 T) at a temperature of 102 K was observed for the x = 0.4 sample. The Curie temperatures decreased from 135 to 102 K for x = 0-0.4, respectively. Moreover, the Weiss constants θ were varied from the positive to negative value with increasing Ca concentration. The antiferromagnetic behavior with Néel temperature around 30 K was found in the x = 0.8 sample. The magnetization measurements show that the hysteresis phenomenon appeared at the temperatures below the Curie or Néel temperatures.
ASJC Scopus subject areas
- Physics and Astronomy(all)