Other materials, instead, are antiferromagnetic, meaning that below the transition temperature (in this case called Neel temperature
, TN), the "compass needles" point in the opposite direction.
Proposing that the blocked state temperature [T.sub.B] =215 K is close to the Neel temperature
, we can expect based on the literature data that the real composition of ferrite garnet nanocrystallites differs significantly from the nominal composition [Bi.sub.2][Dy.sub.1][Fe.sub.4]=[Ga.sub.1][O.sub.12].
(1) The specific heat of [Er.sub.3]Ni is crucial as regenerator material, and above its Neel temperature
, it is ineffective to use since the temperature shifts towards higher side.
BiFeO3 shows G-type antiferromagnetic ordering with Neel temperature
It is found that [Mn.sub.3][Zn.sub.0.9][Cu.sub.0.1]N exhibit a typical AFM-PM transition with the Neel temperature
of [T.sub.N] ~ 163 K.
Data is presented on first- and second-phase transitions, melting lines, crystal structures of the stable and metastable phases, important phase properties such as the Curie and Neel temperature
, and the superconducting temperature.
[omega](k) and density of states of the spin wave excitations the specific heat [c.sub.v](T H) and the mean-field Neel temperature
Also Er[Fe.sub.4][Ge.sub.2] , which disproportionates below the Neel temperature
at 44 K into two different phases, with different magnetic properties, whose relative proportions vary sharply with temperature in response to magnetostriction effects.