Magnetoresistive nature assisted field effect configuration for LaMnO3 / La0·7Ca0·3MnO3 interface

Interface based field effect configuration and charge conduction mechanisms for manganite thin film heterostructures

“…metallic nature) for the LMO/LCMO interface follows the conduction nature of the LCMO thin channel layer whereas resistivity values for the LMO/ LCMO interface are highly contributed by the separate highly resistive semiconducting LMO thin gate layer within the presently studied LMO/LCMO/LAO structure. All the resistivity measurements in the present investigation (as well as in the recent report 37 ) on the interface based modified field effect studies deal with the narrow temperature window between 200 K and 300 K only since earlier reports on the similar investigations for interface based modified field effect studies on the same LMO/LCMO interface within the same LMO/LCMO/LAO structure dealt with a large range of temperature between 5 K and 300 K. 31,32 In these reported investigations, the applied interface electric fields can be found with their lower values (limited to AE1 MV cm À1 , where no considerable effects on LMO/LCMO interface resistivity have been observed) 31,32 whereas the present report deals with comparatively larger applied interface electric fields up to AE4 MV cm À1 (for obtaining possible significant field effects on LMO/LCMO interface resistivity and related charge transport). Also, the ZDE polynomial mechanism has been understood for the obtained interface resistivity behaviors in the reported investigations for the lower values of the temperature window between 5 K and 220 K and found different possible spin fluctuations within the LMO/LCMO manganite interface region.…”

“…01, 901, 1801 and 2701) between applied magnetic field lines and the ab plane of the LMO/LCMO interface. 37 Gohil et al 37 have reported the metallic nature of the LMO/LCMO interface under all studied angles of the applied magnetic field of 1.2 T with an exhibition of negative MR where the negative MR value is found to be strongly dependent on the angle between the applied magnetic field direction and the ab plane of the LMO/LCMO interface. One can realize from Fig.…”

“…10) which can be ascribed to the memory effect (memory effect: once spins get oriented in the direction of the applied magnetic field, they cannot get back to their original directions upon reversal of the applied magnetic field in the antiparallel direction) across the LMO/LCMO interface of the LMO/LCMO/LAO structure. 37 Upon change in the angle from 1801 to 2701, MR can be again enhanced which can be attributed to an improved magnetic energy in the case of 2701. 37 While comparing the MR values for 901 and 2701 angles, one can realize lower MR for the 2701 angle/direction which can be ascribed to the important role of the LAO substrate having a diamagnetic nature since in the case of the 2701 angle, the magnetic field lines first interact with the diamagnetic LAO substrate followed by interaction with the LCMO ferromagnetic metal layer and then interaction with the LMO antiferromagnetic insulator layer.…”

“…In the case of resistivity measurement for the LCMO thin layered channel, four probe contacts of silver were made over the surface of the LCMO thin film, set of two on either side of the LMO thin layer [please refer the right panel (b) of Fig. 3] (also, please refer the detailed contact geometries for all the three cases of LMO, LCMO and LMO/LCMO resistivity measurements in a recent report 37 ). It is worth highlighting from Fig.…”

“…3 Temperature (range: 200 K to 300 K) dependent variation in resistivity for the LMO thin layer (gate layer) using two probe resistivity measurement geometry (resistivity range: O cm), the LCMO thin film (channel layer) using four probe resistivity measurement geometry (resistivity range: mO cm) and the LMO/LCMO interface (interface between the LMO and LCMO layers) using two probe resistivity measurement geometry (resistivity range: O cm) under a zero interface electric field for the LMO/ LCMO/STO structure. 37 Right panel: Silver contact positions on the surfaces of LMO and LCMO thin layers employed for the above mentioned resistivity measurements for the single LMO thin layer, the single LCMO thin film and the LMO/LCMO interface of the LMO/LCMO/LAO structure.…”