Magnetic Susceptibility of Collinear and Noncollinear Heisenberg Antiferromagnets

TitleMagnetic Susceptibility of Collinear and Noncollinear Heisenberg Antiferromagnets
Publication TypeJournal Article
Year of Publication2012
AuthorsJohnston DC
Journal TitlePhysical Review Letters
Date Published08
Type of ArticleArticle
ISBN Number0031-9007
Accession NumberWOS:000307709400038
Keywordscrystal, MNF2, phase-transition, rbcucl3, triangular-lattice

Predictions of the anisotropic magnetic susceptibility chi below the antiferromagnetic (AFM) ordering temperatures T-N of local moment Heisenberg AFMs have been made previously using molecular field theory (MFT) but are very limited in their applicability. Here a MFT calculation of chi(T <= T-N) is presented for a wide variety of collinear and noncollinear Heisenberg AFMs containing identical crystallographically equivalent spins without recourse to magnetic sublattices. The results are expressed in terms of directly measurable experimental parameters and are fitted with no adjustable parameters to experimental chi(T <= T-N) data from the literature for several collinear and noncollinear AFMs. The influence of spin correlations and fluctuations beyond MFT is quantified by the deviation of the theory from the data. The origin of the universal chi(T <= T-N) observed for triangular lattice AFMs exhibiting coplanar noncollinear 120 degrees AFM ordering is clarified.

URL<Go to ISI>://WOS:000307709400038
Alternate JournalPhys. Rev. Lett.