Structure helimagnetic

When, in a helimagnetic structure, a strong uniaxial anisotropy favouring the axis perpendicular to the layers exists, the magnetic moments become... 

Fig. 7.17. Arrangement of magnetic moments in more complex ordered materials (a) a helimagnetic structure (b) a sine wave modulated structure.

As a specific example to clarify the effect of reduced film thickness consider the helimagnetic phase of Dy, which has a c-axis wavelength of about 30 A. The structure has a net moment, and is no longer clearly an antiferromagnet, when the film thickness... 

FeAs 1000- -4.2 650-300 3.1 -1400 Farad, vib. below T = 300 K and above T = 650 K deviation from Curie-Weiss law below 0N = 77 -1-1 K helimagnetic structure broad maximum at T = 250 K depending on previous history of sample 72S20, Fig. 81... 

When a helimagnetic structure is submitted to a field applied along one direction of the plane of the moments, for a field larger than a critical value the structure becomes a fan structure (fig. 120). The regular rotation of the moment in the helimagnetic arrangement... 

In a helical or helimagnetic structure, as sketched in fig. 123, the magnetic moment at site i is given by... 

There is a large variety of single-0 antiferromagnetic structures (sine-wave) ampUtude-modulated, antiphase, simple antiferromagnetic, helimagnetic, etc. 

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