Ferromagnetism antiferromagnetic material

There are several types of magnetic behaviour that affect the specific heat of a material paramagnetism, ferromagnetism, antiferromagnetism and ferrimagnetism. Diamagnetism, being independent of temperature, causes no specific heat contribution and is not considered. 

The change in the Mossbauer spectrum of an antiferromagnetic material produced by an external field is considerably less dramatic than for a ferromagnetic material. Since there is no net moment per unit cell for Hext to interact with, as a first approximation in a randomly oriented antiferromagnet, Hext will increase H in about half the atoms and decrease H in the others, depending on the orientation of an individual atomic spin. The net result is to broaden the lines of the Mossbauer... 

Fig. 11.58 Schematic representations of magnetic dipole arrangements in (a) paramagnetic, (b) ferromagnetic, and (antiferromagnetic materials.

Write down an expression for Curie s law pertaining to paramagnetic materials and for the Curie-Weiss law pertaining to ferromagnetic or antiferromagnetic materials. 

Further reports of Br SSNMR have been tabulated and can be found in Tables 9-17. Very brief summaries are provided within the tables, where appropriate. Although not discussed explicitly here, some / Br SSNMR experiments have been carried out upon sodalite solid solutions (Table 13), as well as paramagnetic, ferromagnetic and antiferromagnetic materials (Table 17). In the latter systems, the NMR experiments have been largely carried out below liquid helium temperature using single crystals. 

With the exception of lattice defects and semiconducting materials, these will not be discussed further here. In Section 20.8, we introduced some concepts of magnetism including ferromagnetism, antiferromagnetism and ferrimag-netism although these properties are important in materials chemistry, it is beyond the scope of this book to take this topic further. 

For ferromagnetic, ferrimagnetic, and antiferromagnetic materials the magnetic field in the above expression is replaced by the magnetization M and the magneto-optic coefficient in this case is known as the Kund constant K ... 

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