We report 51V NMR spectra in the triangular-lattice vanadates, AV10O15, (3d2.2), AV13O18 (3d2.38), and A2V13O22 (3d 1.92) (A = Ba, Sr). These compounds have orbital degrees of freedom and itinerant electrons arising from the partially occupied t2g bands. We show microscopic observations of spin-singlet trimers and antiferromagnetic tertramers with orbital orders in BaV10O 15, but no indication of the orbital order and the spin singlet in SrV10O15. The paramagnetic and nonmagnetic spins coexist in BaV13O22 but only the nonmagnetic spins are present in AV13O18 (A = Ba, Sr). The spin singlet formation in the incommensurate band filling is understood as the incommensurate charge-density wave induced by the 3d orbital order.
|ジャーナル||Journal of Physics: Conference Series|
|出版ステータス||Published - 2012|
|イベント||26th International Conference on Low Temperature Physics, LT 2011 - Beijing, China|
継続期間: 2011 8月 10 → 2011 8月 17
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