Antiferromagnetism in NiTiO3

Abstract

The effective internal field in NiTiO3 as a function of temperature has been determined from zero-field resonance absorption in a powder sample at millimeter wavelengths. Assuming a g value of 2, the resonant frequency (187 kMc) leads to an effective field at 4.2°K of approximately 67 kG. The temperature dependence fits within experimental error a Brillouin function for S = 1, with a Néel temperature of 22°K. From dc susceptibility data, a Néel temperature of 23°K is obtained and an exchange field of approximately 270 kG is computed. These data yield an out-of-plane anisotropy of about 8.3 kG.

New thermodynamic data for CoTiO3, NiTiO3 and CoCO3 based on low-temperature calorimetric measurements

“…Our data for NiTiO 3 show that a lambda-shaped low-temperature heat capacity anomaly occurs at around 26 K (Figure 2), coinciding with the antiferromagnetic transition [15,16,39]. In a similar fashion, CoTiO 3 exhibits a low-temperature heat capacity anomaly peaking at 37 K, which is in excellent agreement with the old structural and magnetic data [18,40].…”

Atomic Layer Deposition of oriented nickel titanate (NiTiO3)

“…The magnetic structures for a selection of them are depicted in Figure 2.4. Below the Néel temperatures, magnetic moments in NiTiO3 (23-26 K) [102,103] and CoTiO3 (37 K) [103] order ferromagnetically within each layer of Ni 2+ /Co 2+ , with non-magnetic layers of Ti 4+ separating the antiferromagnetic coupling along the c axis, similar to FeTiO3 (Figure 2.4 i). Contrary to FeTiO3, the moments are directed perpendicular to the c axis.…”

Antiferromagnetic and Ferrimagnetic Resonance

“…A FM R in uniaxial ilmenites has been, observed by Heller and co workers [42,43] in the range of 2 to 4 mm wavelength radiation. Results for M n T i0 3 (for which K is positive) for both powder and single-crystal materials were discussed by Stickler and Heller [42].…”

“…Results for M n T i0 3 (for which K is positive) for both powder and single-crystal materials were discussed by Stickler and Heller [42]. More recently Heller et al [43] have observed A FM R in powders of N iT i0 3 for which K is negative, and the spins are therefore aligned in the [111] plane. More recently Heller et al [43] have observed A FM R in powders of N iT i0 3 for which K is negative, and the spins are therefore aligned in the [111] plane.…”