Vacancy-induced magnetism in SnO2: A density functional study

We study the magnetic and electronic properties of defects in SnO2 using pseudopotential and all electron methods. Our calculations show that bulk SnO2 is nonmagnetic, but it shows magnetism with a magnetic moment around 4.00 mu(B) due to Sn vacancy (V-Sn). The magnetic moment comes mainly from O atoms surrounding VSn and Sn atoms, which couple antiferromagnetically with the O atoms in the presence of VSn. The coupling between different Sn vacancies is also studied and we found that these defects not only couple ferromagnetically but also antiferromagnetically and ferrimagnetically. Our calculations demonstrate that the experimentally observed giant magnetic moment of transition-metal-doped SnO2 can be attributed to V-Sn.