In this paper we present the results of the synthesis and characterization of nanocrystalline La1-xNaxMnO3+delta samples. Two synthetic routes were employed: polyacrylamide-based sol-gel and propellant synthesis. Pure, single-phase materials were obtained with grain size around 35 nm for the sol-gel samples and around 55 nm for the propellant samples, which moreover present a broader grain size distribution. For both series a superparamagnetic behavior was evidenced by means of magnetization and EPR measurements with peculiar features ascribable to the different grain sizes and morphology. Preliminary magnetoresistivity measurements show enhanced low-field (<1 T) magnetoresistance values which suggest an interesting applicative use of these manganites.
Nanosized Sodium-Doped Lanthanum Manganites : Role of the Synthetic Route on their Physical Properties
MALAVASI, LORENZO;MOZZATI, MARIA CRISTINA;AZZONI, CARLO;FLOR, GIORGIO
2003-01-01
Abstract
In this paper we present the results of the synthesis and characterization of nanocrystalline La1-xNaxMnO3+delta samples. Two synthetic routes were employed: polyacrylamide-based sol-gel and propellant synthesis. Pure, single-phase materials were obtained with grain size around 35 nm for the sol-gel samples and around 55 nm for the propellant samples, which moreover present a broader grain size distribution. For both series a superparamagnetic behavior was evidenced by means of magnetization and EPR measurements with peculiar features ascribable to the different grain sizes and morphology. Preliminary magnetoresistivity measurements show enhanced low-field (<1 T) magnetoresistance values which suggest an interesting applicative use of these manganites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
