Relationship between the synthesis parameters and the morphology of manganite nanoparticle-assembled nanostructures

A.LEYVA, H.TROIANI, C.CURIALE, R.SANCHEZ AND P.LEVY

PHYSICA B - CONDENSED MATTER

ELSEVIER SCIENCE BV

Año: 2007 vol. 398 p. 344 - 347

0921-4526

Abstract Nanoparticles assembled into nanostructures (NAN)of manganese perovskite oxides for different compositions and diameters have been synthesized following a template-assisted method.We discuss the relationship among geometrical,structural and nanostructural parameters observed when synthesizing LaMnO3 ,La0.66 Sr0.33 MnO3 ,La0.66 Ca0.33 MnO3 and La0.325 Pr0.300 Ca0.375 MnO3 manganite based complex oxides.For all the studied compounds,the structures are composed of an assembly of small (some few tens of nanometers) grains.They form nanotubes above some threshold diameter of the template,and nanowires below it.Here we focus on the correlation between grain size and the diameter at which the tube to wire crossover occurs.The threshold for this tube to wall crossover seems to depend on the speci .c compound.We present evidence from TEM observations that allow a rationalization of several phenomena in the synthesis process.O3 ,La0.66 Sr0.33 MnO3 ,La0.66 Ca0.33 MnO3 and La0.325 Pr0.300 Ca0.375 MnO3 manganite based complex oxides.For all the studied compounds,the structures are composed of an assembly of small (some few tens of nanometers) grains.They form nanotubes above some threshold diameter of the template,and nanowires below it.Here we focus on the correlation between grain size and the diameter at which the tube to wire crossover occurs.The threshold for this tube to wall crossover seems to depend on the speci .c compound.We present evidence from TEM observations that allow a rationalization of several phenomena in the synthesis process. r 2007 Elsevier B.V.All rights reserved.2007 Elsevier B.V.All rights reserved.