TY  - JOUR
AU  - Wahyudi, O.
AU  - Ceretti, M.
AU  - Weill, I.
AU  - Cousson, A.
AU  - Weill, F.
AU  - Meven, M.
AU  - Guerre, M.
AU  - Villesuzanne, A.
AU  - Bassat, J.-M.
AU  - Paulus, W.
TI  - Growth of high quality single crystals of strontium doped (Nd,Pr)-nickelates, Nd $_{2−x}$ Sr $_{x}$ NiO $_{4+δ}$ and Pr $_{2−x}$ Sr $_{x}$ NiO $_{4+δ}$
JO  - CrystEngComm
VL  - 17
IS  - 33
SN  - 1466-8033
CY  - London
PB  - RSC
M1  - FZJ-2016-01634
SP  - 6278 - 6285
PY  - 2015
AB  - Large size and high quality single crystals of Nd2−xSrxNiO4+δ and Pr2−xSrxNiO4+δ, with selected composition (x = 0.0, 0.1 and 0.5), were grown by a floating-zone technique using an image furnace. We found that even small deviations from the ideal cation stoichiometry led to either NiO segregation or formation of Ni-poor Pr4Ni3O10−x, or RExOy intergrowth phases, rendering the title compounds unstable even under ambient conditions. Related to potential applications as membranes in SOFC, we importantly found Nd2−xSrxNiO4+δ and Pr2−xSrxNiO4+δ powders, obtained from ground stoichiometric single crystals, to be stable in air at high temperature (1000 °C), contrary to the partial decomposition observed when synthesized as polycrystalline powders by classical solid state synthesis. The presence of NiO/Pr4Ni3O10−x or RExOy intergrowth phases are discussed as a drawback limiting high temperature stability for Pr2NiO4+δ. Grown single crystals were characterised by neutron and X-ray diffraction as well as by electron microscopy (SEM/EDS), revealing their excellent quality in terms of composition, homogeneity and crystallinity. For each crystal, the oxygen content was determined by thermogravimetric analysis in a reductive atmosphere. Transmission electron microscopy highlighted a complex incommensurate structure for Pr2NiO4.25 and Nd2NiO4.25 with a 2D modulation vector related to oxygen ordering.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000359270700004
DO  - DOI:10.1039/C5CE00906E
UR  - https://juser.fz-juelich.de/record/282889
ER  -