Magnetic Resonance and Susceptibility of Several Ilmenite Powders

Abstract

Magnetic susceptibility, paramagnetic resonance, and antiferromagnetic resonance have been measured in MnTi0 3 , FeTi0 3 , CoTi0 3 , and NiTi0 3 . N6el temperatures T N of 65, 56, 37, and 23±2°K, respectively, have been measured. The molar susceptibilities appear to obey a Curie-Weiss law with C m =4.36, 3.37, 3.72, and 1.24°K, and with paramagnetic Curie temperatures 9 P =-219, +32, -9.3, and -11°K, respectively. The effective spectroscopic splitting factors consistent with this law and with paramagnetic resonance are gef f =2.01, 2.13,2.83,2.22±0.01. The susceptibility of MnTi0 3 exhibits a broad peak near 100°K rather than a well-defined peak at TV. No antiferromagnetic resonance was observed in FeTi0 3 , and no paramagnetic resonance was observed in FeTi0 3 or CoTi0 3 . The antiferromagnetic resonant frequencies, extrapolated to 0°K, are 156,145, and 187 kMc/sec for MnTi0 3 , CoTi0 3 , and NiTi0 3 , respectively. A low-frequency mode of 19.1 kMc/sec was also detected in NiTi0 3 . In the system Mni-^Mg^TiOs, both a R and T N decrease roughly linearly with x in the range 0<#<0.075.

Incommensurate crystal supercell and polarization flop observed in the magnetoelectric ilmeniteMnTiO3

“…[3][4][5][6][7][8][9][10]23] X-ray diffraction measurements were performed on a Brüker D8 Advanced DaVinci diffractometer equipped with Cu Kα source, Ni filter, and Lynxeye detector. Powder neutron diffraction was carried out on the HB-2A diffractometer at the High Flux Isotope Reactor (HFIR, Oak Ridge, TN).…”

“…Between the 1950s and 1990s, the magnetic properties of MnTiO3 were studied using magnetometry [3,4], neutron scattering [5][6][7][8], heat capacity [9], and electron paramagnetic resonance. [10] A field applied along this easy axis results in a spin-flop transition into the ab-plane near μ0HSF = 6.5 T. [11] MnTiO3 exhibits quasi-two dimensional behaviour resulting from an accidental cancellation of various, otherwise strong, interplanar exchange interactions. [6,7,12,13] This is in contrast to other 3d ilmenites such as FeTiO3, CoTiO3, and NiTiO3, but the difference in behaviour is largely accounted for by a modification of the Goodenough-Kanamori rules [14] using an excitonsuperexchange mechanism.…”

Evidence of spin lattice coupling in MnTiO 3 : An x-ray diffraction study

“…Here the Mn 2+ ions are magnetic and Ti 4+ ions are non magnetic. This material undergoes paramagnetic (PM) to antiferromagnetic (AFM) transition at ∼ 64 K with a broad anomaly ∼ 100 K. The broad anomaly is attributed to the setting of two dimensional intra layer AFM interactions [4][5][6][7][8][9] . Goodenough has worked out both the intra and inter layer superexchange interactions and have shown mainly two intra layer and three inter layer superexchange interactions 10 .…”

Structural evolution of MnTi0·8Ru0·2O3

“…MnTiO 3 shows quasi-two dimensional antiferromagnetic behaviour because of the accidental cancellation of different inter-layer exchange interactions 3,4 . In this system, the magnetism arises because of the Mn 2+ ions having partially filled dorbitals(3d 5 ). The magnetic properties of some powder ilmenites viz.…”

“…The magnetic properties of some powder ilmenites viz. MnTiO 3 , FeTiO 3 , CoTiO 3 and NiTiO 3 have been studied by J.J Stickler et al 5 . In this study they exhibited the behaviour of magnetic susceptibility measurement with temperature.…”