BARC/PUB/2003/0489

 
 

Field induced two-dimensional ferromagnetic ordering in a gadolinium stearate Langmuir-Blodgett film

 
     
 
Author(s)

Mukhopadhyay, M. K.; Sanyal, M. K.; Mukadam, M. D.; Yusuf, S. M.; and others
(SSPD)

Source

Physical Review-B, 2003. Vol. 68 (17): Article no. 174427

ABSTRACT

Magnetic properties of materials confined to nanometer length scales are providing important information regarding low dimensional physics. Using gadolinium based Langmuir-Blodgett films, we have shown that a two-dimensional short range ferromagnetic order with no spontaneous magnetization occur as the field is applied along the normal to the growth(in-plane)direction. However, along the growth(out-of-plane) direc-tion, we observe expected paramagnetic behavior down to a temperature of 2 K and a field of up to 70 kOe. We found that in-plane saturation moment increases and the field required to get this saturation decreases with decreasing temperature. These results are consistent with the theoretical predictions on isolated two-dimensional spin system having critical point at T=0 . We have provided preliminary explanations of the observed field induced two-dimensional ferromagnetic ordering by considering asymmetric exchange coupling.

 
 
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