采用基于密度泛函的第一性原理方法计算了闪锌矿GaN掺Cr的电子结构和磁性.考虑不同掺杂浓度和位置,计算结果表明,Ga1-xCrxN呈现铁磁基态,Cr原子间是铁磁性耦合并团簇于N原子,Cr原子与最近邻N原子为反铁磁性耦合.我们采用双交换机制解释了磁性来源和机制.计算结果和最近闪锌矿GaN掺Cr的实验结果吻合.
We report the results of a theoretical study of magnetic coupling between Cr atoms doped in cu-bic GaN. The calculations are within the framework of density functional theory. By varying the concen-tration of doped Cr atoms and the sites they occupy,the electronic structure and magnetic properties of Cr - doped cubic GaN are calculated. It is found that the ferromagnetic phase of Ga1-xCrx N is energetically the most preferable state irrespective of the concentration and site occupation of the Cr atom. Cr atoms cluster around N and couple ferromagnetically,while the neighboring N atom is antiferromagnetically cou-pled to the Cr spin in the zinc blende Ga1-xCrx N. The origin of the ferromagnetism in the Cr -doped cu-bic GaN can be understood by double - exchange mechanism. The calculated results are consistent with the recent experimental discovery of ferromagnetism in Cr - doped GaN single cubic phase.
参考文献
| [1] | H. Ohno .Making Nonmagnetic Semiconductors Ferromagnetic[J].Science,1998(5379):951-956. |
| [2] | Sang Eon Park;Hyeon-Jun Lee;Yong Chan Cho;Se-Young Jeong;Chae Ryong Cho;Sunglae Cho .Room-temperature ferromagnetism in Cr-doped GaN single crystals[J].Applied physics letters,2002(22):4187-4189. |
| [3] | Sato K.;Katayama-Yoshida H. .First principles materials design for semiconductor spintronics[J].Semiconductor Science and Technology,2002(4):367-376. |
| [4] | DAS G P;RAO B K;JENAL P .Ferromagnetism in Crdoped GaN:A first-principles calculation[J].Physical Review B:Condensed Matter,2004,69(1-6):214422. |
| [5] | Shigeya KIMURA;Shanthi SUBASHCHANDRAN;Yi Kai ZHOU;Moo Seong KIM;Satoru KOBAYASHI;Shuichi EMURA;Manabu ISHIMARU;Yoshihiko HIROTSU;Shigehiko HASEGAWA;Hajime ASAHI .Epitaxial Growth of Ferromagnetic Cubic GaCrN on MgO Substrate[J].Japanese journal of applied physics,2006(1a):76-78. |
| [6] | Chitta VA;Coaquira JAH;Fernandez JRL;Duarte CA;Leite JR;Schikora D;As DJ;Lischka K;Abramof E .Room temperature ferromagnetism in cubic GaN epilayers implanted with Mn+ ions[J].Applied physics letters,2004(17):3777-3779. |
| [7] | KRESSE G;HAFNER J .Ab initio molecular-dynamics simulation of the liquid-metal-amorphous-semiconduc-tor transition in germanium[J].Physical Review B:Condensed Matter,1994,49:14251-14269. |
| [8] | PERDEW J P;CHEVARY J A;VOSKO S H .Atoms,molecules,solids,and surfaces:Applications of the generalized gradient approximation for exchange and correlation[J].Physical Review B:Condensed Matter,1992,46:6671-6687. |
| [9] | MONKHORST H J;JAMES D P .Special points for Bril-louin-zone integrations[J].Physical Review B:Condensed Matter,1976,13:5188-5192. |
| [10] | XIONG Z H;JIANG F Y;WAN Q X et al.Influence of crystal structure and formation energies of impurities (Mg,Zn and Ca) in zinc blende CaN[J].Transactions of Nonferrous Metals Society of China,2006,16(z2):s854-s857. |
| [11] | Li ST;Ouyang CY .First principles study of wurtzite and zinc blende GaN: a comparison of the electronic and optical properties[J].Physics Letters, A,2005(2/3):145-151. |
| [12] | SINGH R K;WU S Y;H X et al.The role of Cr substitution on the ferromagnetic properties of Ga1-xCaxN[J].Appl Plays Lett,2005,86(1-3):012504. |
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