Local structure analysis of YSZ by Y-89 MAS-NMR

YPdSn and YPd2Sn: Structure, 89Y solid state NMR and 119Sn Mössbauer spectroscopy

“…While continuing our systematic exploration of 45 Sc NMR interaction parameters in relation to the local environments and electronic structures of ternary Sc x T y X z (T¼ transition metal; X¼element of the 3rd, 4th, and 5th main group) intermetallic compounds [6] we are now also pursuing parallel 89 Y investigations on structurally related yttrium compounds. While highresolution solid state 89 Y NMR spectroscopy of diamagnetic insulators has been well-developed by now [7][8][9][10][11][12][13][14], NMR applications to metallic systems have thus far been limited mostly to low-resolution work on the electronic and magnetic properties of yttrium hydrides [15][16][17][18][19], yttrium-iron based alloys [20][21][22] and borocarbides [23]. The only structurally focused high-resolution Mössbauer spectroscopy.…”

ΔThe effect of co-doping on the yttrium local environment and ionic conductivity of yttria-stabilised zirconia

“…This correlates with an increase in the number of sevenfold oxygen-coordinated yttrium ions [6], possibly representing fragments of the delta phase.…”

“…Previous 89 Y NMR measurements have shown the existence of two different yttrium environments over a range of yttrium concentrations [6]. When yttria stabilises zirconia as the cubic phase, the yttrium ions occupy the Zr 4+ 1 Patent is pending on doping technique utilised here.…”

“…Thus, yttrium and calcium ions are expected to be preferentially eightfold oxygen-coordinated in yttria-stabilised and calcia-stabilised zirconia, respectively. Specifically, the preferential eightfold oxygen coordination has been experimentally observed for yttria-stabilised zirconia [6,13,17]. Scandium ions (0.87 Å) are of a similar size to the zirconium ions, and atomistic simulations have suggested no strong preference in positioning [14].…”

“…It has been shown that oxygen vacancies in YSZ only begin to significantly occupy yttrium ion nearest-neighbour sites beyond 10 mol% Y 2 O 3 [6]. It has also been shown that scandium ions in 8 mol% scandia-stabilised zirconia predominately have oxygen vacancies positioned nearest-neighbour to the scandium ions [7].…”