Phase transition, magnetic

For example, 0 describes the temperature dependence of composition near the upper critical solution temperature for binary (liquid + liquid) equilibrium, of the susceptibility in some magnetic phase transitions, and of the order parameter in (order + disorder) phase transitions. 

At lower temperatures, the standard 3D helical order with all chains having not only the same chirality but also the same phase can be established. The two magnetic phase transitions present very different features. In fact, the transition to the... 

This drawback has been overcome by using rare-earth magnetic materials in the coldest part of the regenerator. These materials have a magnetic phase transitions below 15K, with an increase in their heat capacities (see Section 3.6). However, to find a material suitable for sub 4 K applications is still a challenge. 

Fig. 33. Temperature dependence of the susceptibility of GdNi2B2C measured at 1 Tesla on an oriented powder, indicating the two magnetic phase transitions near 20 K and 14 K (after Felner 2001).

Few of the many known ferromagnetic solids are suitable as catalysts for the nondissociative ortho-parahydrogen conversion. This is especially true if measurements are needed in the neighborhood of the magnetic phase transition, Tc. The reasons for this are threefold the solid may decompose at the temperature necessary to free the surface from contaminants, the Curie point may be so low that the experimental difficulties are formidable, and many such solids show strong dissociative conversion activity near Tc. Of the three solids named above none is very satisfactory. 

In the absence of a magnetic phase transition the k+ sites, as in Cr203-Al203, retain considerable activity at 77 K. But the k sites lose about 2 orders of activity. 

AFM , unusual magnetic phase transition Td, displacive transition. 

Keywords manganites, exchange interactions, magnetic phase transitions, phase... 

Magnetic phase transitions at low temperatures. (J. E. River, Transition Metal Chem., 1972, 7, 1). 

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