Sharma Mohit K, Basu Tathamay, Mukherjee K, Sampathkumaran E V
School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175005, Himachal Pradesh, India.
J Phys Condens Matter. 2017 Jan 6;29(8):085801. doi: 10.1088/1361-648X/aa5472.
We report the results of our investigation of magnetic, thermodynamic and dielectric properties of Ca substituted half-doped orthochromite, DyCaFeCrO. Magnetic susceptibility and heat capacity data bring out that this compound undergoes two antiferromagnetic transitions, one at ~132 and the other at ~22 K. These values are higher than those of DyFeCrO. This finding highlights that non-magnetic hole doping in form of Ca in the place of magnetic Dy tends to enhance magnetic transition temperatures in this half-doped orthochromite. We attribute it to possible change in the valence state of Cr/Fe-ion ions due to hole doping. Dielectric anomalies are also seen near the magnetic ordering temperatures indicating magnetodielectric coupling, which is confirmed by magnetic field dependent dielectric studies. The most notable observation is that magnetodielectric coupling strength gets significantly enhanced as compared to DyFeCrO. The results reveal that it is possible to tune magnetodielectric coupling by hole doping in this system.
我们报告了对钙取代的半掺杂正铬铁矿DyCaFeCrO的磁性、热力学和介电性质的研究结果。磁化率和热容量数据表明，该化合物经历了两个反铁磁转变，一个在132K，另一个在22K。这些值高于DyFeCrO的相应值。这一发现突出表明，用非磁性的钙取代磁性的镝进行空穴掺杂倾向于提高这种半掺杂正铬铁矿的磁转变温度。我们将其归因于空穴掺杂导致Cr/Fe离子价态可能发生的变化。在磁有序温度附近也观察到介电异常，表明存在磁电耦合，这一点通过磁场依赖的介电研究得到了证实。最值得注意的观察结果是，与DyFeCrO相比，磁电耦合强度显著增强。结果表明，在该体系中通过空穴掺杂可以调节磁电耦合。
