Physicochemical properties of La(Ba,M)CuFeO5+δ (M = Sr, Ca, Mg) solid solutions

Electrical and Thermal Conduction Behaviors in La‐Substituted GdBaCuFeO5+δ Ceramics

“…(b), the Gd 1− x La x BaCuFeO 5+δ ceramics (0 ≤ x ≤ 0.4) are found to be thermally stable (only 0.4% weight loss at most) in the whole temperature, whereas a large weight loss can be observed in the compound with x = 0.5 at 700 K. One of the possible reasons may be the sample is regarded as the ferrocuprate solid solution between GdBaCuFeO 5+δ and LaBaCuFeO 5+δ . In addition, some articles have reported that the electrical conductivity of LaBaCuFeO 5+δ decreases due to the release of weakly bonded oxygen . Thus, in the present case, the decrease in the electrical conductivity of Gd 0.5 La 0.5 BaCuFeO 5+δ may be dominated by the transport properties of LaBaCuFeO 5+δ .…”

“…In addition, some articles have reported that the electrical conductivity of LaBaCuFeO 5+d decreases due to the release of weakly bonded oxygen. 16,17,24 Thus, in the present case, the decrease in the electrical conductivity of Gd 0.5 La 0.5 BaCuFeO 5+d may be dominated by the transport properties of LaBaCuFeO 5+d . Furthermore, we have investigated the same phenomenon in our previous work on Sm 0.5 La 0.5 BaCuFeO 5+d .…”

“…Due to their natural layered structure and excellent performance, double perovskite‐like oxides with general formula of A′A″B 2 O 5+δ are gaining much attention, where, A′, A″, and B represent rare‐earth metal, alkaline‐earth metal, and transition metal, respectively . The B site atoms and oxygen atoms constitute pyramid structure to connect basic frame, with the A site atoms arrange into it.…”

Crystal structure, thermal and electrotransport properties of NdBa1–xSrxFeCo0.5Cu0.5O5+δ (0.02 ≤ x ≤ 0.20) solid solutions

“…On the temperature dependences of the relative elongation (l/l 0 ) of materials studied an anomaly in a kink near T k = 640-680 K accompanied by the increase the TEC value was detected (Fig. 2b, Table 2), which took place due to the rearrangement of oxygen sublattice of the samples with consequent evolution of oxygen from them in air [24]. TEC values of ceramics in high-temperature region ( HT , T > T k ) were 15-24% larger than in the low-temperature one ( LT , T < T k ) (Table 3).…”

“…According to the results of thermal analysis, near the room temperature all the samples were thermally stable, but, beginning from the temperatures of 623-663 K (T b ) the small mass loss (0.6-0.8%) was detected (Fig. 2a), which took place due to the evolution of the labile (weakly-bonded) oxygen from the samples into environment [24]. Values of T b decreased at x increasing (Fig.…”