Premium
Preparation of Nanosized Perovskite‐Type LaMnO 3 Powders Using the Thermal Decomposition of a Heteronuclear Complex, LaMn(dhbaen)(OH)(NO 3 )(H 2 O) 4
Author(s) -
Aono Hiromichi,
Tsuzaki Mioko,
Kawaura Akihiro,
Sakamoto Masatomi,
Traversa Enrico,
Sadaoka Yoshihiko
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00776.x
Subject(s) - perovskite (structure) , materials science , thermal decomposition , crystallite , thermogravimetric analysis , differential thermal analysis , analytical chemistry (journal) , phase (matter) , fourier transform infrared spectroscopy , crystallography , diffraction , chemistry , chemical engineering , optics , physics , organic chemistry , chromatography , metallurgy , engineering
The heteronuclear LaMn(dhbaen)(OH)(NO 3 )(H 2 O) 4 complex was synthesized and perovskite‐type hexagonal LaMnO 3 was obtained by its thermal decomposition at approximately 700°C. The complex and its decomposition products were analyzed using simultaneous thermogravimetric and differential thermal analysis (TG/DTA), X‐ray diffraction (XRD) analysis, Fourier‐transform infrared (FTIR) spectroscopy, Auger electron spectroscopy (AES), transmission electron microscopy (TEM) characterization, and specific surface area measurements. Although XRD analysis did not show the peaks of LaMnO 3 for the sample sintered at 600°C, the presence of polycrystalline LaMnO 3 together with an amorphous phase was confirmed by TEM‐selected area diffraction. Particle sizes of the samples decomposed at 600° and 700°C were 20 and 50 nm, respectively. For the conventional solid‐state reaction method, XRD results showed the formation of a LaMnO 3 single phase for the samples fired above 1000°C. However, AES showed that the elemental distributions of La, Mn, and O on the surface were not homogeneous even for the sample sintered at 1200°C. The thermal decomposition of the heteronuclear complex at low temperatures allows the synthesis of single‐phase hexagonal LaMnO 3 powders having nanosized particles, homogeneous and free of intragranular pores, which are suitable for electroceramics applications.