Magnetostriction and anisotropy compensation in TbxDy0.9−xNd0.1Fe1.93 [0.2≤x≤0.4]
TL;DR: In this paper, the structure and magnetostriction of TbxDy0.9−xNd0.1Fe1.93 (0.2≤x≤0.4) compounds are investigated.
Abstract: Structure and magnetostriction of TbxDy0.9−xNd0.1Fe1.93 (0.2≤x≤0.4) compounds are investigated. All the compounds are found to stabilize in MgCu2-type C15 cubic Laves phase structure. The easy magnetization direction changes from ⟨100⟩(x=0.2) to ⟨111⟩(x=0.3) through an intermediate state at x=0.25. Anisotropy compensation is realized near x=0.25 for the TbxDy0.9−xNd0.1Fe1.93 compounds. The Laves phase compound Tb0.4Dy0.5Nd0.1Fe1.93 has large spontaneous magnetostriction (1670×10−6) and a low anisotropy at room temperature which could make it a good candidate material for magnetostriction applications.
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01 Sep 1955
TL;DR: In this paper, the authors restrict their attention to the ferrites and a few other closely related materials, which are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present.
Abstract: In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.
2,659 citations
TL;DR: In this paper, a strong grain-oriented pseudo-1-3 epoxy/composite has been fabricated by curing under a moderate magnetic field, which can be attributed to anisotropy compensation, a large magnetostriction coefficient λ 111, EMD lying along the ⟨111⟩ direction, the strong ⟩-textured orientation, and the chain structure.
Abstract: Spin configuration, magnetocrystalline anisotropy compensation, and magnetostriction of TbxDy1−x(Fe0.8Co0.2)2 (0.20 ≤ x ≤ 0.40) compounds have been investigated. Experimental evidence for the anisotropy compensation has been observed directly by performing x-ray diffraction on magnetic-field aligned powders and by evaluating the Mossbauer spectra. The easy magnetization direction (EMD) at room temperature rotates from the ⟨100⟩ (x ≤ 0.27) to the ⟨111⟩ axis (x ≥ 0.32), subjected to the anisotropy compensation between Tb3+ and Dy3+ ions. The strong grain-⟨111⟩-oriented pseudo-1–3 epoxy/composite has been fabricated by curing under a moderate magnetic field. A giant low-field magnetostriction, longitudinal λ|| and linear anisotropic λa (=λ|| − λ⊥) up to 550 and 760 ppm at 3 kOe, respectively, is obtained for Tb0.32Dy0.68(Fe0.8Co0.2)2 composite, which can be attributed to anisotropy compensation, a large magnetostriction coefficients λ111, EMD lying along ⟨111⟩ direction, the strong ⟨111⟩-textured orientation, and the chain structure. The good magnetoelastic properties, besides only containing 27 vol. % alloy particles in the insulating epoxy, make it a promising candidate for magnetostriction applications.
18 citations
TL;DR: In this article, the crystal structure, magnetic properties and magnetostriction of polycrystalline magnetostrictive alloys Nd(Fe1−xCox)1.9 were investigated.
Abstract: The crystal structure, magnetic properties and magnetostriction of polycrystalline magnetostrictive alloys Nd(Fe1−xCox)1.9 were investigated. It was found that the single cubic Laves phase can only be obtained in the samples with x>0.4 by a traditional annealing method. In contrast, the cubic Laves phase exists over the entire composition range studied in the samples annealed under high pressure. Both the Curie temperature and saturation magnetization increase with increasing Co concentration to a maximum at x = 0.2 and then decrease with further increasing x, which could be understood in the frame of rigid band model. The spin phase diagram for Nd(Fe1−xCox)1.9 is constructed to illustrate the arrangement for the easy magnetization direction and crystal structure. The magnetostriction of Nd(Fe1−xCox)1.9 increases with increasing Co concentration and peaks at x = 0.1 and then presents an anomalous behavior when 0.2≤x≤0.6. It is suggested that the external-field-induced lattice strain should be responsible ...
17 citations
TL;DR: In this paper, the Laves phase compound Tb0.9-xNd0.4Dy0.1(Fe0.8Co0.2)(1.93) has a large spontaneous magnetostriction, the coefficient lambda(111) up to about 1640 ppm.
15 citations
TL;DR: The structure, magnetization and magnetostriction of Tb1−xNdx(Fe0.8Co0.2)1.0 alloys have been investigated by means of X-ray diffraction, a vibrating sample magnetometer and a standard strain technique as mentioned in this paper.
13 citations
References
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01 Sep 1955
TL;DR: In this paper, the authors restrict their attention to the ferrites and a few other closely related materials, which are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present.
Abstract: In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.
2,659 citations
TL;DR: In this article, the authors review the fundamental magnetic and magnetostrictive properties of the RFe 2 Laves phases, focusing especially on the complex behavior of the anisotropy and the success of crystal field theory in explaining it.
151 citations
TL;DR: In this article, it was shown that the anomalous [$uuw$]- and [$uv0$]-type axes of easy magnetization have been observed in some cubic rare-earth-iron Laves compounds.
Abstract: Unusual [$uuw$]- and [$uv0$]-type axes of easy magnetization have been observed in some cubic rare-earth-iron Laves compounds. The presence of these directions of spontaneous magnetization can be accounted for, within the phenomenological treatment of the magnetic anisotropy, by including eighth-power direction-cosine terms in the power expansion of the magnetic anisotropy energy. It will also be shown that the single-ion model predicts the existence of these directions. The conditions imposed on the bulk magnetic anisotropy constants are derived. Typical values of these constants in rare-earth-iron Laves phases are calculated using the single-ion model.
98 citations
TL;DR: In this article, the Laves phase compounds YbFe2, NdFe2 and PrFe2 were compared with those of the rest of the RFe2 series leading to the following conclusions : a) the crystalline field at the Rare Earth is not constant throughout the series, b) the isotropic part of the hyperfine field at iron includes a Lorentz term together with spin and (probably) orbital transferred contributions arising from the R.E., c) the anisotropic part of hyperfine fields only partly results from dipolar effects and seems to involve
Abstract: This paper concludes a study of the three Laves phase compounds YbFe2, NdFe2 and PrFe2. The properties of NdFe2 have been thoroughly investigated with a number of techniques including X-ray diffraction, magnetization measurements, 143Nd N.M.R., 57Fe Mossbauer effect and neutron diffraction. Some data is also reported on PrFe2 and YbFe2. The characteristics of these three compounds are compared with those of the rest of the RFe2 series leading to the following conclusions : a) the crystalline field at the Rare Earth is not constant throughout the series, b) the isotropic part of the hyperfine field at the iron includes a Lorentz term together with spin and (probably) orbital transferred contributions arising from the R.E., c) the anisotropic part of the hyperfine field only partly results from dipolar effects and seems to involve both an intrinsic d band contribution and a transferred contribution from the R.E., d) the hyperfine field at the Rare Earth nucleus is higher than the free ion hyperfine field in the second half of the series and lower in the first half of the series these deviations probably
67 citations
TL;DR: Magnetostriction measurements on the cubic Laves phase compounds DyFe 2, HoFe 2 and ErFe 2 over the temperature range 77-300°K are reported in this article.
62 citations