Abstract
Easy axis antiferromagnets usually exhibit a first-order spin-flop transition when the magnetic field is applied along the easy axis. Recently a colossal magnetoelectric effect was discovered in Ni3TeO6, suggesting a continuous spin-flop transition across a narrow phase in this material [Oh et al., Nat. Commun. 5, 3201 (2014)]. Additional evidence is, however, desirable to verify this mechanism. Here we measure the infrared vibrational properties of Ni3TeO6 in high magnetic fields and demonstrate that the phonon anomalies are consistent with a second-order mechanism.