BARC/PUB/2014/1044

 
 

Disorder-induced Room Temperature Ferromagnetism in Glassy Chromites

 
     
 
Author(s)

Araujo, C. M.; Nagar, S.; Ramzan, M.; Shukla, R.; Tyagi, A. K.; and others
(ChD)

Source

Scientific Reports, 2014. Vol. 4: Article no. 4686

ABSTRACT

We report an unusual robust ferromagnetic order above room temperature upon amorphization of perovskite [YCrO3] in pulsed laser deposited thin films. This is contrary to the usual expected formation of a spin glass magnetic state in the resulting disordered structure. To understand the underlying physics of this phenomenon, we combine advanced spectroscopic techniques and first-principles calculations. We find that the observed order-disorder transformation is accompanied by an insulator-metal transition arising from a wide distribution of Cr-O-Cr bond angles and the consequent metallization through free carriers. Similar results also found in YbCrO3-films suggest that the observed phenomenon is more general and should, in principle, apply to a wider range of oxide systems. The ability to tailor ferromagnetic order above room temperature in oxide materials opens up many possibilities for novel technological applications of this counter intuitive effect.

 
 
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