Effect of grain boundary layer strain on the magnetic and transport properties of (100−x) La0.7Ca0.3MnO3/(x) BaTiO3 composites showing enhanced magnetoresistance

Influence of BTO phase on structural, magnetic and electrical properties of LCMO

“…The EDX results show that the grains which are smaller in size and mainly distributed at the grain boundaries and on the surfaces of LCMO grains are of BTO phase. These results reconfirm the coexistence of both types of grains in agreement with the previous results [7,21]. Microstructure of the composites is found to be significantly different from that of the parent sample due to the strain induced in the system because of presence of BTO grains, as explained by Bose et al [7] also.…”

“…In this paper, we have made a detailed study of structural, electric, magnetic and magnetoresistive behaviours of a homogeneous composite series, (100−x)La 0.67 Ca 0.33 MnO 3 -(x)BaTiO 3 , where La 0.67 Ca 0.33 MnO 3 (LCMO) and BaTio 3 (BTO) are the CMR and FE materials respectively. Interestingly, we have observed double peak behavior of -T curves for our composite samples unlike the previous results [6,7]. We have also observed a simultaneous occurrence of IMR and EMR effects even at high field and an enhanced EMR effect with the increase of field strength.…”

“…Bose et al [7] have explained that boundary layer strain caused by the second phase (BTO in their case) is an important factor for the variation of magnetic and other properties of bulk FM-FE composite system [7]. So far we have come across only few reports on the composites consisting of CMR and FE materials [6,7,18]. Some of these results are quite contradictory and not very thorough, which has insisted us to make more investigations on such series for a wide range of compositional ratio and magnetic field in order to have a better understanding.…”

“…The MR originated from the suppression of spin fluctuations, when spins are aligned on application of magnetic field, [4] is known as IMR. Attempts have also been made to increase the MR through the formation of some composites [6][7][8][9]. This grain boundary MR or EMR is generally ascribed to the intergrain tunneling of spin polarized conduction electrons [10].…”

“…Inclusion of perovskite FE material like BTO, in magnetic CMR substance having similar structure, enhances the MR value. Bose et al [7] have explained that boundary layer strain caused by the second phase (BTO in their case) is an important factor for the variation of magnetic and other properties of bulk FM-FE composite system [7]. So far we have come across only few reports on the composites consisting of CMR and FE materials [6,7,18].…”