Electrical resistivity measurements on the Mn2O3-Mn3O4 phase transformation

Propagation of the contact‐driven reduction of Mn2O3 during reactive flash sintering

“…The power consumption of Mn 3 O 4 during stage III is greater than that of Mn 2 O 3 . Mn 3 O 4 has a higher resistivity than Mn 2 O 3 , and the currents are similar for both samples . The higher power density seen in Figure supports the conclusion that the transformation from Mn 2 O 3 to Mn 3 O 4 is responsible for the increase in power density of the Mn 2 O 3 flash, as shown in Figure .…”

“…Mn 3 O 4 has a higher resistivity than Mn 2 O 3 , and the currents are similar for both samples. 21 The higher power density seen in Figure 6 supports the conclusion that the transformation from Mn 2 O 3 to Mn 3 O 4 is responsible for the increase in power density of the Mn 2 O 3 flash, as shown in Figure 2. The flash onset power density of Mn 3 O 4 also falls within the range 7-50 mW/mm 3 .…”

“…As stage III is held and the sample transforms into Mn 3 O 4 , the temperature read by the thermocouple increases. Mn 3 O 4 has a higher resistivity than Mn 2 O 3 and would experience more Joule heating for the same current . So, as more of the sample becomes Mn 3 O 4 , more power is consumed (as seen in Figure ) and the temperature of the sample increases.…”

Promising alloys for intermediate-temperature solid oxide fuel cell interconnect application

“…The composition of the spinel layer formed on the Fe-Cr-Mn alloys was found to be close to Mn 1.5 Cr 1.5 O 4 [40]. Table 2 lists some physical properties for the various oxides [41][42][43][44][45] that might exist in the oxide scales formed on the alloys studied in this paper. As shown in Table 2, the electrical resistance of the mixed Mn 2 O 3 /TiO 2 and/or spinel layer can be ignored compared to the Cr 2 O 3 inner layer, as both Mn 2 O 3 and Mn 1.5 Cr 1.5 O 4 possess significantly higher electrical conductivity than Cr 2 O 3 , while TiO 2 has a slightly higher electrical resistance than Cr 2 O 3 ; furthermore, the outer layer is much thinner than the Cr 2 O 3 inner layer, as shown in Fig.…”

Ferrimagnetic spinels in hydrothermal and thermal treatment of MnxFe2−2x(OH)6−4x

“…These reactions, the oxidation and transformation into bixbyite, occur simultaneously at x =0.7 and 0.8, giving an acute exothermic effect at ~650~ At x=0.9, the same transformations take place at ~780~ The exothermic effect at 400~ for x = 1 is connected with the formation of a species Mn~ x Mn~ v 08, while the small endothermic peak at ~600~ corresponds to the endothermic transition MnsOs--)ot-Mn203 (partritgeite). The deep peak at ~960~ is an indication of the conversion of partritgeite into hausmannite [23,24] and not to the transition ot---)~-hausmannite [25], since, as a rule, polymorphous transitions do not produce deep, acutely marked effects in DTA.…”