We present theoretical studies of magnetism in II-VI magnetic nanocrystals (NCs) containing single electron coupled to substitutional magnetic ions Mn 2+. By using exact diagonalization techniques, we explore the magnetic phases of magnetic polarons in NCs doped with few Mn2+ ions, as functions of NC size, Mn number and positions. We show that ferromagnetic magnetic polarons (MPs) are stably formed in small magnetic NCs due to strong quantum confinement. By contrast, magnetic polarons with short ranged Mn-clusters in larger NCs exhibit various distinct magnetic phases, from ferromagnetism (FM) to anti-ferromagnetism (AF), sensitively depending on NC size. The stability of magnetic polarons in NCs with arbitrary number of Mn ions are analyzed within a proposed solvable model, supported by the numerical results calculated by using local mean field theory (MFT).
|Number of pages||4|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|State||Published - 30 Sep 2009|
|Event||5th International Conference on Semiconductor Quantum Dots, QD 2008 - Gyeongju, Korea, Republic of|
Duration: 11 May 2008 → 16 May 2008