Mössbauer characterization of 119Sn4 + Dopant ions in the antiferromagnetic ilmenite NiTiO3

✍ Scribed by P.B. Fabritchnyi; A. Wattiaux; M.V. Korolenko; M.I. Afanasov; C. Delmas

• Book ID: 104093635
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 862 KB
• Volume: 149
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2009.06.002

✦ Synopsis

Magnetic hyperfine splitting of the 119 Sn 4+ nuclear levels in the antiferromagnetic NiTiO 3 was for the first time observed using the Mössbauer effect. For the majority of the 119 Sn 4+ dopant ions, the saturation value of the transferred hyperfine field (at 4.2 K, H = 5.25 T) is found to be equal to that previously reported for 119 Sn 4+ in the antiferromagnetic MnTiO 3 . This finding shows that in both ilmenites the spin polarization of Sn 4+ is produced by the divalent cation half-filled e 2 g orbitals involved in interlayer superexchange interactions and implies the location of the dopant within titanium (111) layers. The principal V zz component of the EFG at the Sn 4+ site in NiTiO 3 is found to have a positive sign and be aligned along the [111] axis, as it was the case for Sn 4+ in MnTiO 3 . Lattice-sum calculations on the basis of a simple ionic point-charge model, lead to an erroneous result (in either titanate the sign of V zz on the Ti 4+ site would be negative) and thus demonstrate their failure in identifying the Sn sites.