Superparamagnetic behavior and giant magnetoresistance in oxygen deficient R0.67Sr0.33MnOz (R=Nd, Pr) epitaxial films (abstract) : The 40th annual conference on magnetism and magnetic materials
Ju, H. L. ; Li, Qi ; Xiong, G. C. ; Venkatesan, T. ; Greene, R. L.
[S.l.] : American Institute of Physics (AIP)
Published 1996
[S.l.] : American Institute of Physics (AIP)
Published 1996
ISSN: |
1089-7550
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Source: |
AIP Digital Archive
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Topics: |
Physics
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Notes: |
We have studied the magnetic and magnetotransport properties of oxygen deficient R0.67Sr0.33MnOz (R=Nd, Pr) films and have observed superparamagnetic behavior in these films. The superparamagnetism is indicated by (i) the increasing spread between zero field cooled (ZFC) and field cooled (FC) magnetization curves as temperature decreases, (ii) a sharp drop of the ZFC magnetization at low temperature, (iii) enhanced Curie–Weiss constant above the ferromagnetic temperature, and (iv) at low temperature a sharp drop of coercivity (Hc) with increasing temperature. These findings strongly suggest that all oxygen deficient manganites are magnetically inhomogeneous; i.e., ferromagnetic clusters exist. We estimate the spin cluster diameter to be 7–10 nm at low temperature (T〈30 K). We discuss a possible origin of the giant magnetoresistance effect based on the existence of spin clusters. © 1996 American Institute of Physics.
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Type of Medium: |
Electronic Resource
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URL: |