Investigation of the magnetism of dilute magnetic semiconductors (DMSs) by changing particle dimensionality and doping concentration and its complete understanding is a major step toward their application in multifunctional devices. The importance of effects, such as magnetization reversal with size and magnetic invariance with respect to doping concentration for an appropriate functioning of DMS systems, is empirically well-known. However, explicit demonstration of these effects, specifically in nanomaterials, has so far not been studied mainly due to the lack of synthetic handle. In this work, we have demonstrated the prerequisites of DMS materials by isolating origins of magnetism arising due to clustering of magnetic dopant ions as well as sp–d exchange interaction with the host. We have studied magnetism with varying concentrations of dopant ions and have shown that the magnetism arising due to exchange interaction with the host is invariant up to 10% doping concentration, demonstrating the concentration scaling in DMS systems. Additionally, the study of size-dependent magnetic behavior revealed the effect of domain size and disordered spin on the surface, leading to a change in magnetization/ion as well as magnetization reversal.

中文翻译：

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稀磁半导体量子点中磁性的体积和浓度标度

通过改变颗粒尺寸和掺杂浓度来研究稀磁性半导体（DMS）的磁性及其完整的理解是迈向将其应用于多功能设备的重要一步。对于DMS系统的适当功能而言，诸如对于尺寸的磁化反转和相对于掺杂浓度的磁不变性的影响的重要性在经验上是众所周知的。然而，到目前为止，主要由于缺乏合成处理，尚未对这些作用的明确证明，特别是在纳米材料中进行研究。在这项工作中，我们通过隔离由于磁性掺杂离子的聚集以及与主体之间的sp–d交换相互作用而产生的磁性起源，证明了DMS材料的先决条件。我们研究了不同浓度掺杂剂离子的磁性，并表明由于与主体之间的交换相互作用而产生的磁性在10％的掺杂浓度下是不变的，这说明了DMS系统中的浓度标度。此外，对尺寸依赖性磁行为的研究揭示了磁畴尺寸和表面无序自旋的影响，从而导致磁化/离子变化以及磁化反转。