Unconventional critical behavior in the quasi-one-dimensional S=1 chain NiTe2O5

Abstract

Here we report a quasi-one-dimensional S = 1 chain compound NiTe2O5. From the comprehensive study of the structure and magnetic properties on high-quality single-crystalline NiTe2O5, it is revealed that NiTe2O5 undergoes a transition into an intriguing long-range antiferromagnetic order at T-N = 30.5 K, in which longitudinal magnetic moments along the chain direction are ferromagnetically ordered, while their transverse components have an alternating ferromagnetic-antiferromagnetic coupling. Even though the temperature dependence of magnetic susceptibility represents an archetypal anisotropic antiferromagnetic order, we found that critical behavior of unconventional nature with alpha' similar to 0.25 and beta similar to 0.18 is accompanied by the temperature evolution of the antiferromagnetic order parameter. ©2019 American Physical Society