Gaikwad Swati K, Kharat Shahaji P, Haritha Keerthi, Kolekar Yesh D, Ramana C V
Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra, India.
Department of Physics, Fergusson College (Autonomous), Pune 411004, Maharashtra, India.
Inorg Chem. 2023 Jul 31;62(30):11837-11848. doi: 10.1021/acs.inorgchem.3c01117. Epub 2023 Jul 14.
The design and development of electromagnetic and magnetoelectric materials with enhanced properties and performance are desirable for numerous technologies, which are based on integrated electromagnetic materials and components. Nevertheless, engineering the crystalline materials with multi-complex chemistry and multiple cations is challenging. In this context, herein, we report on the effect of rare-earth (RE) cations, namely, Dy and Tb, co-substituted into the Co-Ni-mixed ferrite materials for applications in stress/torque sensors. The RE-cations that co-substituted Co-Ni-ferrite materials with a composition of NiCoFe(DyTb)O ( = 0-0.1, = 0.3; NCFDT) were prepared by the high-temperature solid-state chemical reaction method. The effect of variable composition () on the structure, morphology, chemical bonding, and magnetic properties of NCFDT materials is investigated in detail, and the structure-property optimization enabled realizing magnetostrictive NCFDT for sensor applications. X-ray diffraction analysis coupled with Rietveld refinement confirms the face-centered cubic crystal structure. Chemical bonding analysis made using Raman spectroscopic and Fourier transform infrared spectroscopic measurements validates the active modes corresponding to the spinel ferrite structure. The effect of Dy and Tb substitution is primarily seen in the grain size (range of 5-15 μm), as evident from the scanning electron microscopy patterns. Energy-dispersive spectroscopy confirms the presence of all constituent elements with expected composition and without any impurities. The magnetic property measurements indicate that the remnant magnetization () increases from 0.06 to 0.17 μ/f.u. with the rare-earth (Dy and Tb) substitution and has achieved the maximum squareness ratio (/) = 0.097 at = 0.10. To validate their application potential in magneto-mechanical sensors, we have measured the magnetostriction coefficients (λ and λ), which demonstrate high values of λ = -92 ppm (along the parallel direction) and λ = 66 ppm (along the perpendicular direction) for NCFDT with = 0.05 at 7000 Oe. In addition, the maximum value of strain sensitivity is observed, particularly = -0.764 nm/A whereas = 0.361 nm/A. The correlation between strain sensitivity (dλ/d) and susceptibility (d/d), as derived from magnetostriction and magnetization measurements, respectively, is established. The outcomes of this study indicate that Ni-Co-ferrites with Dy and Tb substitution are suitable for stress/torque sensors. These NCFDT ferrites may also be useful as a necessary constitutive phase for the manufacture of magnetoelectric composite materials, making them appropriate for magnetic field sensors and energy harvesting applications.
对于众多基于集成电磁材料和组件的技术而言，设计和开发具有增强性能的电磁和磁电材料是十分必要的。然而，设计具有多复杂化学组成和多种阳离子的晶体材料具有挑战性。在此背景下，我们报告了稀土（RE）阳离子，即Dy和Tb，共掺杂到Co-Ni混合铁氧体材料中在应力/扭矩传感器中的应用效果。通过高温固态化学反应法制备了共掺杂Co-Ni铁氧体材料，其组成为NiCoFe(DyTb)O（ = 0 - 0.1， = 0.3；NCFDT）。详细研究了可变组成（）对NCFDT材料的结构、形貌、化学键合和磁性能的影响，并通过结构-性能优化实现了用于传感器应用的磁致伸缩NCFDT。X射线衍射分析结合Rietveld精修证实了面心立方晶体结构。利用拉曼光谱和傅里叶变换红外光谱测量进行的化学键合分析验证了与尖晶石铁氧体结构相对应的活性模式。从扫描电子显微镜图像可以明显看出，Dy和Tb取代的主要影响体现在晶粒尺寸（5 - 15μm范围内）。能量色散光谱证实了所有组成元素的存在，其组成符合预期且无任何杂质。磁性能测量表明，随着稀土（Dy和Tb）取代，剩余磁化强度（）从0.06增加到0.17μ/f.u.，并且在 = 0.10时实现了最大矩形比（/） = 0.09）。为了验证它们在磁机械传感器中的应用潜力，我们测量了磁致伸缩系数（λ和λ），结果表明，在7000 Oe下， = 0.05的NCFDT的λ = -92 ppm（沿平行方向）和λ = 66 ppm（沿垂直方向）具有较高值。此外，观察到了最大应变灵敏度值，特别是 = -0.764 nm/A，而 = 0.361 nm/A。分别从磁致伸缩和磁化测量中得出了应变灵敏度（dλ/d）和磁化率（d/d）之间的相关性。本研究结果表明，Dy和Tb取代的Ni-Co铁氧体适用于应力/扭矩传感器。这些NCFDT铁氧体也可能作为制造磁电复合材料的必要组成相有用，使其适用于磁场传感器和能量收集应用。
