DOI QR코드

DOI QR Code

Cr2Te3에서 쿨롱 상관효과의 크기와 자기모멘트 크기의 계산

Calculation of the Magnitude of the Coulomb Correlation and Magnetic Moment of Cr2Te3

  • 윤석주 (경상대학교 사범대학 과학교육학부 물리전공 및 기초과학연구소) ;
  • 권세균 (POSTECH 화학과 기능성분자계 연구단)
  • Youn, Suk-Joo (Department of Physics Education and Research Institute of Natural Science, Gyeongsang national University) ;
  • Kwon, Se-Kyun (Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology)
  • 발행 : 2006.04.01

초록

자기구조가 복잡한 것으로 알려져 있는 $Cr_2Te_3$의 전자구조와 자기구조를 이론적 방법으로 연구하였다. LDA+U 방법에 의해 Cr-d 전자의 상관효과를 고려해서 계산하면 전자의 상태밀도와 자기모멘트가 국소밀도근사(LDA)에 의한 것보다 실험과 더 잘 일치하는 것을 보였다. 이 과정에서 $Cr_2Te_3$에서 Cr-d 전자의 상관효과의 크기 U=1.7 eV를 구했다. $Cr_2Te_3$의 강자성 상태와 준강자성 상태의 에너지가 같아서 축퇴된다면 실험에서 알려진 Cr의 자기모멘트를 설명할 수 있음을 보였다.

Electronic and magnetic structure of $Cr_2Te_3$ have been studied, which is a material with complex magnetic structure. Density of states and magnetic moments show better agreement with experiments than LDA if they are obtained with the correlation effect of Cr-d electrons taken into account by the LDA+U method. In these calculations, the magnitude of the correlation effect is found to be 1.7 eV. It is shown that the magnitude of experimental magnetic moments of Cr atoms can be explained if the ferromagnetic states and the ferrimagnetic states have the same energy to be degenerate.

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