Colossal Positive Magnetoresistance in Oxygen-Deficient Ca4Mn3O10

Huge changes in resistance induced by an external magnetic field, i.e., a colossal magnetoresistance effect, is a long-lived theme of the research due to both fundamental science and device applications. Careful analysis of oxygen-deficient Ca
₄
Mn
₃
O
₁₀
, synthesized by the citric acid method, establishes a direct correlation between magnetic and electric properties. An electric resistive anomaly at the magnetic ordering temperature of ~115 K supports this correlation. We currently report on a colossal positive magnetoresistance up to ~1300% below the metal-to-insulator transition temperature for oxygen-deficient Ca
₄
Mn
₃
O
₁₀
. The positive magnetoresistance effect in this system may be attributed to the field-induced carrier localization.