3/10/93

مجتبي اعلايي، فرهاد فضيله

فيزيك

ID8681

AbstractDiscovery of magnetism arising from p orbitals opened a new eld in the area of magnetism Binaryionic compounds su as CaN are among these novel magnetic systems whi exhibit half metallicproperty in the hypotehtical zincblende and ro salt structures hence may be promissing materials forSpintronics A er a brief review of p magnetism in these binary ionic compounds we discuss the FPLAPWmethod implemented in the FLEUR code and used for this project In this method crystal space isdivided into three regions atomic spheres interstitial and vacuum regions and the full potential isused in all regions en we discus basic and practical aspects of noncolinear magnetism including therequired te niques for calculation of ex ange parameters magnon spectra and Curie temperature In the section three we calculate the ground state properties of CaN and CaP in the ro salt and zinc blende structures Using the energy curves in terms of volume the structural properties of these alloysare extracted It is seen that CaN in both ro salt and zinc blende structures exhibits half metallicferromagnetism while CaP in the ro salt structure is a nonmagnetic metal In the section four the magnon spectrum ex ange parameters and Curie temperature of bulkCaN and CaP in the ro salt and zinc blende structures are calculated In order to determine theCurie temperature of the systems we use mean eld MFA and random phaes RPA approximations It is predicted that CaN in the zinc blende structure has a Curie temperature considerably higher thanthe room temparature In the h section we calculate the magnetic properties and magnon spectrum of CaN and CaPmonolayers and CaN CaP Superla ice in the ro salt structure and compare the results with bulkproperties Keywords CaN p magnetism half metal ro salt zinc blende FPLAPW noncolinear mag netism ex ange constant magnon spectrum monolayer Superla ice

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مجتبي اعلايي، فرهاد فضيله