Investigation of Structural, Optical and Electrical Transport Properties of Yttrium Doped La0.7Ca0.3MnO3 Perovskites

Polaron hopping conduction mechanism and magnetic properties of Pb‐doped LaMnO3

“…The resistivity ( ρ ) vs. temperature ( T ) plots for La 1‐x Pb x MnO 3 (0 ≤ x ≤ 0.20) in the temperature range of 10–300 K are presented in Figure 7. It revealed that the resistivity drops as the temperature increases for the pristine sample, which suggests semiconducting nature of the prepared LaMnO 3 and no transition is found for this sample 30,39 . However, samples doped with Pb exhibit different behavior of resistivity with the increase in temperature.…”

“…A few peaks are also detected at ~1305 cm −1 that resemble the stretching vibrations of C–O. A band at 1490 cm −1 is associated with the C = C vibrations and at 1580 cm −1 relates to the C = O, which is due to the absorption of CO 2 on the surface of the samples 30 . Additionally, the vibrational bands that appeared at 3435 cm −1 are allocated to the vibration of hydroxyl group that may be owing to the absorbed water and strong stretching vibrational mode of the O–H group, whereas the mode at 3250 cm −1 corresponds to the weak stretching vibrational mode of O–H group (symmetric and antisymmetric) of the bound water molecule 31 .…”

“…Modeling of infiltration of liquids in porous media is a well-studied subject, especially in the field of hydrology where it is used to model seepage of water through porous soils and rocks. 29,30 The physics of resin flow into a mold under pressure is similar to the seepage problem and so similar approaches have been used also to model the flow of resin into a mold containing fiber mats. 23,[31][32][33][34][35][36][37][38] The models are used in these cases to determine the resin flow front and mold filling times corresponding to different infiltration conditions.…”

“…It revealed that the resistivity drops as the temperature increases for the pristine sample, which suggests semiconducting nature of the prepared LaMnO 3 and no transition is found for this sample. 30,39 However, samples doped with Pb exhibit different behavior of resistivity with the increase in temperature. All Pb-doped samples exhibit a metal to semiconductor transition (MST) at various temperatures.…”

“…Studies o derived SiC ceramic 25 and SiC/SiC c shown that porosity decreases and mecha prove with the increasing number of PIP show that increasing pyrolysis temperatu tration of SiC fillers in polycarbosilane improved mechanical properties in two-d SiC (C/SiC) composites fabricated using Starting with pyrolysis of a "cured prepreg-based composite, each processin process involves infiltration of a precera porous ceramic preform followed by a py which the polymer is converted into ceram cess modeling is focused on these two ste Modeling of infiltration of liquids in well-studied subject, especially in the where it is used to model seepage of wa soils and rocks. 29,30 The physics of resin under pressure is similar to the seepage pr lar approaches have been used also to mod into a mold containing fiber mats. 23,[31][32][33][34][35][36][37][38] T in these cases to determine the resin flow ing times corresponding to different infilt Preceramic polycarbosilane polymers as precursors to make ceramic fibers 10,3 trix.…”