A neutron-diffraction experiment was performed to measure the critical scattering from a percolating antiferromagnet RbMn0.31Mg0.69F3, whose magnetic concentration is just at the percolation concentration for a cubic lattice, cp = 0.312. The magnetic scattering was observed at around the superlattice point (1/2, 1/2, 1/2). We found that the scattering function exhibits a non-Lorentzian line shape, S(q) = (q2 + κ2)-x (q and κ are the momentum transfer and the inverse correlation length, respectively), with the exponent x = 0.6 ± 0.1 at the low temperature of 1.6 K, and that the exponent is attributed to the fractal structure of the percolating network. Also, the system was found to exhibit a crossover to the homogeneous state at high temperature.
|Journal||Applied Physics A: Materials Science and Processing|
|Publication status||Published - 2002 Dec|
ASJC Scopus subject areas
- Materials Science(all)