Behaviour at ok and at different magnetic fields of the double magnetic helix

• Published in: The Journal of physics and chemistry of solids 1983, Vol.44 (8), p.765-772
• Main Authors: Plumier, R., Sougi, M., Lecomte, M., Bidaux, R.
• Format: Article
• Language: English
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/0022-3697(83)90008-2

We study the behaviour at 0K and at all magnetic field values up to the magnetic saturation of the magnetic helix in which two distinct magnetic ions of spin lengths S 1, and S 2 are acted on by two unequal molecular fields. Although limited to the case of zigzag and collinear chains on which only the magnetic interactions J between first nearest neighbours ( n.n) and J 1, or J 1 between second n.n. are considered, complex phase diagrams are obtained. The most disclosing features show up by taking S 1, S 2, J 1, J 2 as parameters and h, J as variables. Whereas the biconical configuration appears as the most general solution, triangular and oblique configurations also exist in finite field in all ( h, J) diagrams. In addition, a collinear ferrimagnetic configuration is found to be stable for definite h and J values. We finally observe that according to the ratio values S 1 S 2 and (J 2J 1) 1 2 , eight types of ( h, J) diagrams exist which differ from each other by distinct approaches to the ferri- or ferromagnetic alignment.