论文标题
微波合成的LA0.5BA0.5COO3中的磁截图3
Magnetostriction in microwave synthesized La0.5Ba0.5CoO3
论文作者
论文摘要
单相多晶LA0.5BA0.5BA0.5COO3-D样品在处理时间的20分钟内通过微波辐射合成，并研究了其结构，磁性，电气和磁性性能。尽管H = 0.5 KOE的场冷却磁化（M）的温度依赖性表明TC = 177 K处的铁磁过渡的开始，但零场冷却和场冷却M（T）之间的不可逆性甚至在h = 3 KOE处仍然存在。在10 K处的m（h）在最大可用场上不饱和，并且比1.9μb/co的值小得多（0.87μb/co在50 koE中的0.87μb/co）预期可用于中间CO3+和CO4+旋转的旋转贡献。电阻率显示出降至10 K的绝缘行为，并且在TC周围仅发生少量磁力（H = 70 KOE）。所有这些结果表明，磁性异质的基态，具有弱相互作用的铁磁簇与非有效磁相共存。样品的长度沿施加的磁场的方向扩展（正磁尾），即使在50 KOE处也不会显示饱和。磁截图在10 K时具有最大值（= 252 ppm），并且随温度升高而降低。与LA0.5SR0.5COO3上的可用数据相比，磁截图的值较小，这表明非铁磁矩阵很可能是抗铁磁磁性的，并且限制了在微波合成的LA0.5BA0.5BA0.5BA0.5BA0.5COO3-D-DCOO3-D-d样品中野外诱导的铁磁簇的扩展。
A single-phase polycrystalline La0.5Ba0.5CoO3-d sample was synthesized by microwave irradiation within 20 minutes of processing time and its structural, magnetic, electrical, and magnetostrictive properties were investigated. While the temperature dependence of field-cooled magnetization (M) in a field of H = 0.5 kOe indicates the onset of ferromagnetic transition at TC = 177 K, irreversibility between the zero field-cooled and field cooled M(T) persists even at H = 3 kOe. M(H) at 10 K does not saturate at the maximum available field and has a much smaller value (0.87 μB/Co in a field of 50 kOe) than 1.9 μB/Co expected for spin-only contribution from intermediate Co3+ and Co4+ spins. The resistivity shows insulating behavior down to 10 K and only a small magnetoresistance (~ 2% for H = 70 kOe) occurs around TC. All these results suggest a magnetically heterogeneous ground state with weakly interacting ferromagnetic clusters coexisting with a non-ferromagnetic phase. The length of the sample expands in the direction of the applied magnetic field (positive magnetostriction) and does not show saturation even at 50 kOe. The magnetostriction has a maximum value (= 252 ppm) at 10 K and it decreases with increasing temperature. The smaller value of magnetostriction compared to the available data on La0.5Sr0.5CoO3 suggests that non-ferromagnetic matrix is most likely antiferromagnetic and it restrains the field-induced expansion of ferromagnetic clusters in the microwave synthesized La0.5Ba0.5CoO3-d sample.
