论文标题
巡回Ferromagnet Srru $ _ {1-x} $ ti $ _x $ o $ $ _3 $中的电子属性
Electronic properties in itinerant ferromagnet SrRu$_{1-x}$Ti$_x$O$_3$
论文作者
论文摘要
在这里，我们研究了4 $ d $的铁磁材料srruo $ _3 $及其ti取代的srru $ _ {1-x} $ ti $ _x $ _3 $ $ _3 $ series（$ x $ $ $ \ $ $ $ 0.7）。 srruo $ _3 $是一种金属，显示了具有过渡温度的流动铁电磁作用$ t_c $ \ sim $ 160 k。已经观察到金属到绝缘体过渡的$ x $ $ \ sim $ 0.4。信号金属状态（$ x $ $ \ leq $ 0.4）和绝缘状态（$ x $ $> 0.4 $> $ 0.4）的电荷运输性质遵循修改的Mott的可变范围跳跃模型。在铁磁金属状态下，电阻率显示了低于$ t_c $的$ t^2 $依赖性，尽管在低温下对$ t^{3/2} $依赖性修饰。在Ti取代样品中，$ t^{3/2} $依赖性的温度范围扩展到更高的温度。有趣的是，在存在磁场的情况下，这种$ t^{3/2} $依赖性在整个铁磁状态中占主导地位。电子传输行为的这种演变可以在费米液体理论和电子马格诺散射机制的框架内解释。负磁场表现出滞后和与磁场的负值和正值之间的交叉，这与串联的磁行为有关。 $ x $的特定热量的降低电子系数支持当前系列中的绝缘行为增加。我们计算了Srruo $ _3 $的高kadowaki-woods比率（$ x $ $ \ leq $ 0.3），随着替代浓度的增加。这表示随着替代浓度的增长电子相关效应。
Here, we study the electrical transport and specific heat in 4$d$ based ferromagnetic material SrRuO$_3$ and its Ti substituted SrRu$_{1-x}$Ti$_x$O$_3$ series ($x$ $\le$ 0.7). The SrRuO$_3$ is a metal and shows itinerant ferromagnetism with transition temperature $T_c$ $\sim$ 160 K. The nonmagnetic Ti$^{4+}$ (3$d^0$) substitution would not only weaken the active Ru-O-Ru channel but is also expected to tune the electronic density and electron correlation effect. A metal to insulator transition has been observed around $x$ $\sim$ 0.4. The nature of charge transport in paramagnetic-metallic state ($x$ $\leq$ 0.4) and in insulating state ($x$ $>$ 0.4) follows modified Mott's variable range hopping model. In ferromagnetic-metallic state, resistivity shows a $T^2$ dependence below $T_c$ which though modifies to $T^{3/2}$ dependence at low temperature. In Ti substituted samples, temperature range for $T^{3/2}$ dependence extends to higher temperature. Interestingly, this $T^{3/2}$ dependence dominates in whole ferromagnetic regime in presence of magnetic field. This evolution of electronic transport behavior can be explained within the framework of Fermi liquid theory and electron-magnon scattering mechanism. The negative magnetoresistance exhibits a hysteresis and a crossover between negative and positive value with magnetic field which is connected with magnetic behavior in series. The decreasing electronic coefficient of specific heat with $x$ supports the increasing insulating behavior in present series. We calculate a high Kadowaki-Woods ratio ($x$ $\leq$ 0.3) for SrRuO$_3$ which increases with substitution concentration. This signifies an increasing electronic correlation effect with substitution concentration.
