Room temperature ferromagnetism in un-doped amorphous HfO<sub>2</sub> nano-helix arrays<xref ref-type="fn" rid="cpb142144fn1">*</xref>

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) Hysteresis curves of samples measured at room temperature, (b) room temperature M _s versus the sample morphology.