Abstract
Usingthereal-spaceHartree-Fockapproximation,themagneticphasediagramofafive-orbitalHubbardmodelfortheiron-basedsuperconductorsisstudiedvaryingtheelectronicdensitynintherangefromfivetosevenelectronspertransitionmetalatom.TheHubbardinteractionUisalsovaried,atafixedHundcouplingJ/U=0.25.Severalqualitativetrendsandavarietyofcompetingmagneticstatesareobserved.Atn=5,arobustG-typeantiferromagneticinsulatorisfound,inagreementwithexperimentalresultsforBaMn2As2.Asnincreasesawayfrom5,magneticstateswithanincreasingnumberofnearest-neighborsferromagneticlinksbecomeenergeticallystable.Thisincludesthewell-knownC-typeantiferromagneticstateatn=6,theE-phaseknowntoexistinFeTe,andalsoavarietyofnovelstatesnotfoundyetexperimentally,someoftheminvolvingblocksofferromagneticallyorientedspins.Regionsofphaseseparation,asinMnoxides,havealsobeendetected.Comparisontoprevioustheoreticalinvestigationsindicatethatthesequalitativetrendsmaybegenericcharacteristicsofphasediagramsofmulti-orbitalHubbardmodels.
