Critical exponents closely matching those of the $N=2$ chiral universality class have been obtained for the layered magnetic system cobalt glycerolate using muon spin relaxation. This class was originally introduced to represent geometrically frustrated triangular stacked-layer $XY$ magnets with chiral noncollinear spin structures. Since the present magnetic system is a canted $XY$ system without geometrical frustration or chiral degeneracy, the results indicate that the order parameter for canting in this system plays a similar role to the chiral order parameter in the geometrically frustrated systems, strongly suggesting that both types of noncollinear system share the same universality class.

• Received 9 January 2007

DOI:https://doi.org/10.1103/PhysRevLett.99.017202