Critical Magnetic Neutron Scattering from CoO
Abstract
The critical magnetic neutron scattering from CoO has been measured near the Néel temperature T_{N}. The diffuse intensity at various wave vectors was assumed proportional to A_{+}TT_{N}1^{γ} above T_{N} and A_{}TT_{N}1^{γ'} below T_{N}. Using the method of AlsNielsen, we measured the temperature dependence of the critical scattering at several values of q [the displacement from the (111) position in reciprocal space] and used these data to calculate the relative magnitudes of γ and γ'. In order to satisfy scaling law requirements we referred our measurements to a rigid lattice by correcting for the large tetragonal contraction below T_{N}. We found that γ'=(1.02+/0.02)γ, and this suggests that static scaling laws may apply to CoO. In addition we ascertained that A_{+}A_{}≅7.6+/1.5 in agreement with the linear theory of Schofield, where A_{+}A_{}=6.0+/0.8 for CoO.
 Publication:

Physical Review Letters
 Pub Date:
 June 1971
 DOI:
 10.1103/PhysRevLett.26.1480
 Bibcode:
 1971PhRvL..26.1480R