Annealed Ising model with competing interactions on a Bethe lattice

Haroni, AA; Paraskevaidis, CE

dc.contributor.author	Haroni, AA	en
dc.contributor.author	Paraskevaidis, CE	en
dc.date.accessioned	2014-03-01T01:11:42Z
dc.date.available	2014-03-01T01:11:42Z
dc.date.issued	1996	en
dc.identifier.issn	0370-1972	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11787
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0030533584&partnerID=40&md5=9a2db395b7cba844babef023f532b824	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	CAYLEY TREE	en
dc.subject.other	ALLOYS	en
dc.subject.other	BEHAVIOR	en
dc.title	Annealed Ising model with competing interactions on a Bethe lattice	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1996	en
heal.abstract	Frustration effects which appear in an annealed Ising-type system with two types of magnetic atoms (alpha = A,B) on the sites of a Bethe lattice with branching ratio 2 are studied. Competing magnetic interactions between nearest neighbors (J(alpha alpha')) and next-nearest neigbors (J'(alpha alpha) J ''(alpha alpha')) in the presence of an external magnetic field are considered. The distribution of the magnetic atoms on the sites of the Bethe lattice is determined, aside from the magnetic interactions, by spin-independent interactions (U) over bar(alpha alpha'),(U) over bar'(alpha alpha'),(U) over bar ''(alpha alpha)', and by the chemical potential applied to the system. An iterative scheme for the renormalized effective nearest-neighbor (magnetic) couplings and the effective fields is applied. This scheme reduces the study of an N-layer Bethe lattice to the study of a cluster consisting of four lattice points. The effective fields along with the effective nearest-neigbor couplings of the central cluster contain all the information for the thermodynamic state of the system. The phase diagrams of these systems contain, besides the ferromagnetic and the paramagnetic, a) a four-cycle antiferromagnetic (AF-2) phase and b) a modulated phase (M) consisting: of commensurate and incommensurate regions. In the case of strong coupling between magnetic atoms of different species, the phase diagrams are enriched by the presence of a modulated antiferromagnetic (MAF) region. The information of modulation persists even within the ferromagnetic phase.	en
heal.publisher	AKADEMIE VERLAG GMBH	en
heal.journalName	Physica Status Solidi (B) Basic Research	en
dc.identifier.isi	ISI:A1996TX34300018	en
dc.identifier.volume	193	en
dc.identifier.issue	2	en
dc.identifier.spage	445	en
dc.identifier.epage	456	en