Recently reported magnetic quantum paraelectric properties in M-type hexaferrite single crystals have encouraged us to study the dielectric response of SrFe12O19 nanocrystallites down to the temperature of 10 K. As Sc-induced multiferroicity, promising for electromagnetic control, has been reported in bulk and films of hexaferrites, we also studied the size effect in dielectric response of Sr0.95Nd0.05Fe12-xScxO19 nanocrystallites with x = 0.36, 1.08, and 1.56. The nanopowders were obtained by citric method and the phase purity and the microstructure were controlled using X-ray diffraction and scanning electron microscopy. No clear evidence of quantum paraelectric behavior has been observed in temperature variation of dielectric permittivity of SrFe12O19 nanopowder. In the case of Nd-stabilized Sc-doped nanocrystallites, a low-temperature dielectric relaxation, similar to that in dipolar glasses, has been discovered. Activation energy of 62.5 meV was obtained for the lowest doping level and a modest increase in the energy was found at higher Sc concentrations. We relate the low-temperature relaxation in Sc-doped hexaferrite nanopowder to dielectric displacive polarization at the 4e Wyckoff sites modified by Sc-ions substituting the ferric ions in 4f2 and 12k positions.Recently reported magnetic quantum paraelectric properties in M-type hexaferrite single crystals have encouraged us to study the dielectric response of SrFe12O19 nanocrystallites down to the temperature of 10 K. As Sc-induced multiferroicity, promising for electromagnetic control, has been reported in bulk and films of hexaferrites, we also studied the size effect in dielectric response of Sr0.95Nd0.05Fe12-xScxO19 nanocrystallites with x = 0.36, 1.08, and 1.56. The nanopowders were obtained by citric method and the phase purity and the microstructure were controlled using X-ray diffraction and scanning electron microscopy. No clear evidence of quantum paraelectric behavior has been observed in temperature variation of dielectric permittivity of SrFe12O19 nanopowder. In the case of Nd-stabilized Sc-doped nanocrystallites, a low-temperature dielectric relaxation, similar to that in dipolar glasses, has been discovered. Activation energy of 62.5 meV was obtained for the lowest doping level and a modest incre...

中文翻译：

---

纳米晶 Sr0.95Nd0.05Fe12-xScxO19 六铁氧体的偶极类玻璃介电响应

最近报道的 M 型六铁氧体单晶的磁量子顺电特性鼓励我们研究 SrFe12O19 纳米微晶在 10 K 温度下的介电响应。因为 Sc 诱导的多铁性，有希望用于电磁控制，已经在块体和薄膜中得到了报道对于六铁氧体，我们还研究了 x = 0.36、1.08 和 1.56 的 Sr0.95Nd0.05Fe12-xScxO19 纳米微晶的介电响应中的尺寸效应。通过柠檬酸法获得纳米粉末，并使用X射线衍射和扫描电子显微镜控制相纯度和微观结构。在 SrFe12O19 纳米粉末的介电常数的温度变化中没有观察到量子顺电行为的明确证据。在 Nd 稳定的 Sc 掺杂纳米微晶的情况下，已发现低温介电弛豫，类似于偶极玻璃中的弛豫。在最低掺杂水平下获得了 62.5 meV 的活化能，并且在较高的 Sc 浓度下发现了能量的适度增加。我们将掺杂 Sc 的六铁氧体纳米粉末的低温弛豫与 4e Wyckoff 位点的介电位移极化相关联，这些位点由 Sc 离子取代 4f2 和 12k 位置的三价铁离子修饰。 最近报道的 M 型六铁氧体单晶中的磁量子顺电特性鼓励我们研究 SrFe12O19 纳米微晶在 10 K 温度下的介电响应。由于 Sc 诱导的多铁性，有望用于电磁控制，已在六铁氧体的块体和薄膜中得到报道，我们还研究了介电响应的尺寸效应Sr0.95Nd0。05Fe12-xScxO19 纳米微晶，x = 0.36、1.08 和 1.56。通过柠檬酸法获得纳米粉末，并使用X射线衍射和扫描电子显微镜控制相纯度和微观结构。在 SrFe12O19 纳米粉末的介电常数的温度变化中没有观察到量子顺电行为的明确证据。在 Nd 稳定的 Sc 掺杂纳米微晶的情况下，已经发现了低温介电弛豫，类似于偶极玻璃中的弛豫。在最低掺杂水平和适度增加的情况下获得了 62.5 meV 的活化能。在 SrFe12O19 纳米粉末的介电常数的温度变化中没有观察到量子顺电行为的明确证据。在 Nd 稳定的 Sc 掺杂纳米微晶的情况下，已经发现了低温介电弛豫，类似于偶极玻璃中的弛豫。在最低掺杂水平和适度增加的情况下获得了 62.5 meV 的活化能。在 SrFe12O19 纳米粉末的介电常数的温度变化中没有观察到量子顺电行为的明确证据。在 Nd 稳定的 Sc 掺杂纳米微晶的情况下，已经发现了低温介电弛豫，类似于偶极玻璃中的弛豫。在最低掺杂水平和适度增加的情况下获得了 62.5 meV 的活化能。