Room temperature ferromagnetism in un-doped amorphous HfO2 nano-helix arrays*
Xie Qian, Wang Wei-Peng, Xie Zheng, Zhan Peng, Li Zheng-Cao, Zhang Zheng-Jun†
       
(a) XRD patterns of the as-prepared samples, (b) EDX result with SAED image in the inset.