Effects of Co and Fe addition on the properties of lanthanum strontium manganite

Synthetic Methods for Perovskite Materials; Structure and Morphology

“…According to some studies (Kuharuangrong et al, 2004), Co doping of 20% does not usually influence the grain size of LSM, but 40 % mol Co significantly reduces the grain size (about 5-10 µm) of the La 0.84 Sr 0.16 Mn 1-x Co x O 3 (x= 0, 0.2, 0.4) samples prepared by conventional oxide mixing process. However, some reduction in the particle size was observed in the case of La 0.67 Pb 0.33 Mn 1-x Co x O 3 (x= 0 and 0.3) compounds, which were also prepared by the ceramic route (Dhahri et al, 2010).…”

Characterization of perovskite-type cathode, La0.75Sr0.25 Mn0.95−xCox Ni0.05O3+δ (0.1≤x≤0.3), for intermediate-temperature solid oxide fuel cells

“…scandia-stabilized zirconia (ScSZ), Ce 0.9 Gd 0.1 O 1.95 (CGO) and La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3 (LSGM) [2]. An attempt was also made to increase the catalytic activity of LSM (Sr 2+ content = 0.16, 0.4 or 0.5 mol) by doping Fe 2+ , Co 2+ or Ni 2+ (≤0.4 mol) in the Mn-site [9][10][11][12][13]. The doping decreased the electrical conductivity of LSM; however, the coefficient of thermal expansion was increased for Co 2+ -doping, and left invariant for Fe 2+ -and Ni 2+ -doping.…”

Effect of strontium ion doping on structural, thermal, morphological and electrical properties of a co-doped lanthanum manganite system

“…It may also contain a small fraction of the di-valent cations such as Mn 2+ (0.83 Å) and Ni 2+ (0.69 Å). As the Co 2+ -and Ni 2+ -doping result in a decrease in the volume of the LSM, while the Fe 2+ -doping leads to an opposite trend [9][10][11][12], one may expect concentrations of the cations, e.g., Mn 3+ , Mn 4+ , Fe 4+ , Co 3+ and Ni 2+ in the LSMFCN (x = 0.3 mole) such a way that the volume became almost equal to that of the LSM (x = 0.3 mole). However, the co-doping largely helped to enhance the oxygen vacancies as observed by the thermogravimetry study, which has been discussed below.…”

“…It may be due to a reduction in the available sites of Mn 3+ for polaron hopping and disturbance of the conductive Mn 3+ -O-Mn 4+ network by the B (=Fe, Co and/or Ni) ions [4][5][6][7][8][9][10][11][12]. The positively charged oxygen vacancies can behave as traps for moving electrons [26].…”