Abstract
We investigate theoretically the prospects of ferromagnetism being induced by cation vacancies in nonmagnetic oxides. A single Ca vacancy VCa0 has a magnetic moment due to its open-shell structure but the ferromagnetic interaction between two vacancies extends only to four neighbors or less. To achieve magnetic percolation on a fcc lattice with such an interaction range one needs a minimum of 4.9% vacancies, or a concentration 1.8×1021cm-3. Total-energy calculations for CaO show, however, that due to the high vacancy formation energy even under the most favorable growth conditions one can not obtain more than 0.003% or 1018cm-3 vacancies at equilibrium, showing that a nonequilibrium vacancy-enhancement factor of 103 is needed to achieve magnetism in such systems.
Original language | American English |
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Article number | 107203 |
Number of pages | 4 |
Journal | Physical Review Letters |
Volume | 96 |
Issue number | 10 |
DOIs | |
State | Published - 2006 |
NREL Publication Number
- NREL/JA-590-39260