Magnetoresistive, magnetic and thermoelectric properties of the La_0.7Ba_0.3MnO₃/xNiO system are studied. The x-ray diffraction shows the coexistence of the NiO and the La_0.7Ba_0.3MnO₃ phases in doped composites, revealing their interaction lack. This suggests the precipitation of the NiO at grain boundaries and on the La_0.7Ba_0.3MnO₃ surface, interrupting the conduction between grains. Hindering the direct contact between the La_0.7Ba_0.3MnO₃ grains increases the resistivity and decreases the metal-semiconductor transition temperature, leading to the spin tunneling effect. This enhances the room temperature magnetoresistance of the La_0.7Ba_0.3MnO₃ compound from -11.25% to -42.7% and -17.24% for 5% and 20% of the NiO additive amount, respectively. The pristine La_0.7Ba_0.3MnO₃ compound shows a Curie temperature value of 348K that fluctuates negligibly with the NiO addition. However, it decreases to 332K in the x=0.05 composite due to a tiny diffusion of NiO in the La_0.7Ba_0.3MnO₃ lattice at this composite. The thermoelectric power properties of the La_0.7Ba_0.3MnO3 compound are changed with the NiO addition. Where the hole conduction interval increases and the peak of Seebeck coefficient is shifted towards higher temperatures.

研究了La _0.7 Ba _0.3 MnO ₃ / x NiO体系的磁阻，磁和热电性质。X射线衍射显示掺杂复合材料中NiO和La _0.7 Ba _0.3 MnO ₃相共存，表明它们之间没有相互作用。这表明NiO在晶界和La _0.7 Ba _0.3 MnO ₃表面上的沉淀，中断了晶粒之间的导电。阻碍La _0.7 Ba _0.3 MnO ₃之间的直接接触晶粒增加电阻率并降低金属-半导体的转变温度，从而导致自旋隧穿效应。对于NiO添加量的5％和20％，这将La _0.7 Ba _0.3 MnO ₃化合物的室温磁阻分别从-11.25％提高到-42.7％和-17.24％。原始的La _0.7 Ba _0.3 MnO ₃化合物的居里温度值为348K，随添加NiO的变化可忽略不计。但是，由于NiO在La _0.7 Ba _0.3 MnO _3中的微小扩散，在x = 0.05复合材料中它减少到332K此复合材料上的晶格。La _0.7 Ba _0. 3MnO3化合物的热电性能随NiO的添加而变化。空穴传导间隔增加并且塞贝克系数的峰值移向更高的温度。