We report a Co–MgF/MgF heterostructure that comprises periodic layers of super-paramagnetic Co0.23–(MgF)0.77 and thin crystalline MgF, to tailor the frequency response of tunneling magneto-dielectric (TMD) effect. The results indicate that increasing MgF interlayer thickness (t) from 0 to 4 nm causes the position of peak dielectric change (Δe′/e′0) at a specific frequency fTMD, to shift from 300 to 3 kHz, while also retaining a slight decrease in Δe′/e′0 from 2.9% to 2.4%. The magnitude of Δe′/e′0 can be controlled by varying the Co content in the granular layers. Theoretical curve fittings predict that the TMD effect in the heterostructure arises from both the granular layers and interlayers, and a change in inter-granular distance within the interlayers leads to a shift in the position of fTMD. This study may prove helpful for tailoring the magneto-dielectric response of granular nanocomposites to a particular frequency, with potential magnetoelectric applications over a wide frequency range.We report a Co–MgF/MgF heterostructure that comprises periodic layers of super-paramagnetic Co0.23–(MgF)0.77 and thin crystalline MgF, to tailor the frequency response of tunneling magneto-dielectric (TMD) effect. The results indicate that increasing MgF interlayer thickness (t) from 0 to 4 nm causes the position of peak dielectric change (Δe′/e′0) at a specific frequency fTMD, to shift from 300 to 3 kHz, while also retaining a slight decrease in Δe′/e′0 from 2.9% to 2.4%. The magnitude of Δe′/e′0 can be controlled by varying the Co content in the granular layers. Theoretical curve fittings predict that the TMD effect in the heterostructure arises from both the granular layers and interlayers, and a change in inter-granular distance within the interlayers leads to a shift in the position of fTMD. This study may prove helpful for tailoring the magneto-dielectric response of granular nanocomposites to a particular frequency, with potential magnetoelectric applications over a wide frequency range.

中文翻译：

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通过原位插入薄 MgF2 层在 Co-MgF2 颗粒纳米结构中定制隧道磁介电效应

我们报告了一种 Co-MgF/MgF 异质结构，它包括超顺磁性 Co0.23-(MgF)0.77 和薄结晶 MgF 的周期性层，以定制隧道磁介电 (TMD) 效应的频率响应。结果表明，将 MgF 夹层厚度 (t) 从 0 nm 增加到 4 nm 会导致特定频率 fTMD 下峰值介电变化 (Δe'/e'0) 的位置从 300 kHz 移动到 3 kHz，同时也保持轻微的Δe'/e'0 从 2.9% 减少到 2.4%。Δe'/e'0 的大小可以通过改变颗粒层中的 Co 含量来控制。理论曲线拟合预测异质结构中的 TMD 效应来自颗粒层和层间，层间内颗粒间距离的变化导致 fTMD 位置的偏移。这项研究可能证明有助于将颗粒纳米复合材料的磁介电响应调整到特定频率，并在很宽的频率范围内具有潜在的磁电应用。我们报告了一种 Co-MgF/MgF 异质结构，它包括超顺磁性 Co0.23 的周期性层–(MgF)0.77 和薄结晶 MgF，以定制隧道磁介电 (TMD) 效应的频率响应。结果表明，将 MgF 夹层厚度 (t) 从 0 nm 增加到 4 nm 会导致特定频率 fTMD 下峰值介电变化 (Δe'/e'0) 的位置从 300 kHz 移动到 3 kHz，同时也保持轻微的Δe'/e'0 从 2.9% 减少到 2.4%。Δe'/e'0 的大小可以通过改变颗粒层中的 Co 含量来控制。理论曲线拟合预测异质结构中的 TMD 效应来自颗粒层和层间，层间内颗粒间距离的变化导致 fTMD 位置的偏移。这项研究可能有助于将颗粒纳米复合材料的磁介电响应调整到特定频率，并在很宽的频率范围内具有潜在的磁电应用。