Showing papers on "Ferrimagnetism published in 1982"
TL;DR: In this article, the fundamental properties of hexagonal ferrites with magnetoplumbite structure were discussed, and the most typical way to obtain the ferrimagnetic hexagonal oxides as powder or in a sintered polycrystalline state is the solid-state reaction of heating the mixtures of constituent oxides or of compounds that are easily changed to oxides by heating.
Abstract: Publisher Summary This chapter discusses the fundamental properties of hexagonal ferrites with magnetoplumbite structure. Ferrimagnetic properties of the magnetoplumbite type compounds are naturally based on the superexchange interaction of Fe–O–Fe, so that no remarkable effect on the magnetic properties would be expected by the replacement of a Ba ion. However, the properties could be influenced to some extent by the changes in the distance or the angle between Fe–O–Fe arising from the substitution, leading to differences among BaM, SrM, and PbM. Further, the most typical way to obtain the ferrimagnetic hexagonal oxides as powder or in a sintered polycrystalline state is the solid–state reaction of heating the mixtures of constituent oxides or of compounds that are easily changed to oxides by heating. BaCO 3 , SrCO 3 , PbO, and α-Fe 2 O 3 are generally used as starting materials, but oxalates, sulfates, chlorides, nitrates, or hydroxides are also used for specific purposes. Proper reaction temperature, atmosphere, and cooling conditions should be chosen according to the phase diagrams. However, single-phase M type compounds can be usually obtained by heating in air between 800 °C and 1200°C, and just removing from the furnace.
181 citations
TL;DR: In this paper, a modified magnetic phase diagram is suggested for the spinel system (AB2O4) in which the A and B sites are partially (or completely) occupied by magnetic atoms.
Abstract: The article by Villain [Z. Phys. B — Condensed Matter33, 31 (1979)] is discussed and a modified magnetic phase diagram is suggested for the spinel system (AB2O4) in which theA andB sites are partially (or completely) occupied by magnetic atoms. This diagram takes into account the antiferromagnetic exchange interactionsJAA,JBB andJAB between nearest neighbor cations of various types. Regions of paramagnetic, antiferromagnetic, ferrimagnetic and possible spin glass behaviour are indicated on the diagram.
73 citations
TL;DR: In this article, the magnetic properties of microcrystals are discussed on the basis of results obtained by use of M?ssbauer spectroscopy, and the anisotropy energy constants of micro-crystals of Fe, Co, Ni and Fe3O4 are found to change upon chemisorption.
Abstract: The magnetic properties of microcrystals are discussed on the basis of results obtained by use of M?ssbauer spectroscopy. Spectra of microcrystals with dimensions smaller than about 100 A are influenced by magnetic fluctuation effects such as superparamagnetic relaxation and collective magnetic excitations, and these effects allow a determination of the product of the particle size and the magnetic anisotropy energy constant. Measurements on ferromagnetic and ferrimagnetic particles as a function of applied magnetic fields allow a determination of the particle volume. The anisotropy energy constants of microcrystals of Fe, Co, Ni and Fe3O4 are found to change upon chemisorption. Spectra of small particles at low temperatures also give information on the magnetic properties of the atoms in the surface layer. These studies as well as thin film studies show that no magnetically dead layers are present at the surface of the samples. In the case of metallic iron an enhanced magnetic hyperfine field is found, in agreement with theoretical results.
73 citations
TL;DR: In this paper, the crystal structures, magnetic characteristics of hexagonal ferrites, and chemical processes for their production are discussed, and reactions in salt melts or under hydrothermal conditions produce finely divided pigments whose particles have a pronounced hexagonal, plate-like habit, a narrow particle size distribution, and advantageous magnetic properties.
Abstract: Owing to their particular crystallographic properties, ferrimagnetic hexagonal ferrites exhibit a far greater coercive force than the conventional magnetic pigments. They therefore appear to be suitable for use in magnetic information storage procedures, some of which are novel and are at the development stage. Thus, magnetic tapes of high coercive force containing barium ferrite could be used as master tapes for copying magnetic information or for producing forgery-proof magnetic cards, if magnetic heads having high-order write fields were successfully developed. Moreover, platelet-like ferrite pigments in which the preferred direction of magnetic orientation is perpendicular to the plane of the platelet are of great interest for perpendicular magnetic recording.
In this progress report, the crystal structures, magnetic characteristics of hexagonal ferrites, and chemical processes for their production are discussed. In particular, reactions in salt melts or under hydrothermal conditions produce finely divided pigments whose particles have a pronounced hexagonal, plate-like habit, a narrow particle size distribution, and advantageous magnetic properties. The magnetic properties of the pigments crystallized from salt melts may be adjusted by cation exchange.
65 citations
TL;DR: In this paper, the magnetic behavior of basalt glass and glass-ceramic was studied by magnetization measurements between 4 and 800 K as a function of a wide range of magnetic fields (H) between 0 and 60 kG.
Abstract: The magnetic behaviour of a basalt glass and glass-ceramic was studied by magnetization measurements between 4 and 800 K as a function of a wide range of magnetic fields (H) between 0 and 60 kG. For the as-annealed glass it was found that nearly all the iron ions behaved as paramagnetic ions. In the samples heat-treated at 700 and 900°C, the magnetization (M) values showed three magnetic components: paramagnetic Fe2+ ions, magnetite in a superparamagnetic and in a ferrimagnetic state. This confirmed our previous Mossbauer results. The superparamagnetic behaviour of the fine particles of magnetite was interpreted by Langevin's theory. From the M (H) and M(T) values we evaluated the percentage of each component as a function of temperature, the magnetization values in the saturated states, the mean particle diameter and the particle size distributions.
41 citations
TL;DR: In this paper, the magnetic behavior of one-dimensional exchange-coupled systems with first-row transition metals (Co, Ni, Cu) was studied. But the magnetic properties of these systems were not investigated.
Abstract: We report on the magnetic behaviour of one-dimensional exchange-coupled systems MM′EDTA·6H2O, where M and M′ are two host sites for first-row transition metals (Co, Ni, Cu).The isolated complexes are either homometallic chains with one kind of magnetic cation or heterometallic chains with two distinct cations in the regular sequence ⋯A—B—A—B⋯.
30 citations
02 Aug 1982
TL;DR: In this article, the crystal structures and the molecular engineering techniques utilized to prepare aligned uniaxial hexagonal compounds with controlled anisotropy fields up to values of 50 Koe are reviewed.
Abstract: Ferrimagnetic oxides with hexagonal crystal structures (referred to as hexagonal ferrites) are characterized primarily by their foliate (leaf-like or platelet) structure and high anisotropy fields. These properties allow for the preparation of polycrystalline grain oriented magnetic compounds with controlled values of anisotropy fields and attendant preferred direction of magnetization. These highly anisotropic aligned polycrystalline hexagonal ferrite compoundspossess built-in effective magnetic fields (up to 50 kilo-oersteds) in both uniaxial and planar structures, with associated electrical properties appropriate for many application considerations in signal control and processing components at millimeter wave frequencies. This paper reviews the crystal structures and the molecular engineering techniques utilized to prepare aligned uniaxial hexagonal compounds with controlled anisotropy fields up to values of 50 Koe. The properties of these compounds important to millimeter wave applications are summarized.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
27 citations
TL;DR: In this article, a surface permeability expression for the dispersion of magnetostatic waves propagating in two close proximity ferrimagnetic films was derived using the technique of surface permeabilities, and two modes of propagation for volume waves were identified respectively as symmetric and antisymmetric modes from the symmetry of the rf magnetization.
Abstract: Using the technique of ’’surface permeabilities,’’ an expression is derived for the dispersion of magnetostatic waves propagating in two close proximity ferrimagnetic films. Two modes of propagation for volume waves are identified respectively as the symmetric and antisymmetric modes from the symmetry of the rf magnetization. Useful group delay behavior is shown to result from films of equal thickness. Some measurements are reported using two yttrium iron garnet films sandwiching simple single finger transducers. Difficulties in exciting the symmetric forward volume mode are explained in terms of the coupling coefficients for these double film structures.
24 citations
TL;DR: In this article, the electrical conductivity of mixed Co-Zn ferrites was studied as a function of composition and temperature, and the existence of the single-phase spinel structure was established by X-ray analysis of the specimens.
Abstract: The electrical conductivity of mixed CoZn ferrites was studied as a function of composition and temperature. The existence of the single-phase spinel structure was established by X-ray analysis of the specimens. The Seebeck coefficient for these ferrites was determined in order to discuss the conductivity which is explained in terms of the hopping mechanism. Plots of the logarithm of conductivity versus the reciprocal temperature are almost linear and show a transition near the Curie temperature. The activation energy in the paramagnetic region is higher than that in the ferrimagnetic region.
23 citations
TL;DR: In this article, the crystal and magnetic properties of Dy 2 Fe 17, Dy 6 Fe 23, DyFe 3 and DyFe 2 intermetallic compounds are investigated with X-ray, magnetometric, 57 Fe and 161 Dy Mossbauer effect methods.
23 citations
TL;DR: In this article, the sign and magnitude of the exchange constants in Y3Fe5O12 have been explained on the basis of Anderson's theory of superexchange, and the low temperature magnetisation data in Dy3Fe 5O12 has been explained by assuming canting on the c sublattice.
Abstract: The exchange constants in the ferrimagnetic garnets R3 Fe5 O12 (R=Y3+, Gd3+ and Dy3+) have been obtained from the experimental data on saturation magnetisation and inverse susceptibility. The sign and magnitude of the exchange constants in Y3Fe5O12 have been explained on the basis of Anderson’s theory of superexchange. The low temperature magnetisation data in Dy3Fe5O12 have been explained by assuming canting on thec sublattice.
TL;DR: The ThMn12 type structure RFe5Al7 intermetallic compounds display a wide variety of unusual magnetic phenomena: huge thermal and magnetic hysteresis as mentioned in this paper.
TL;DR: In this article, the results of magnetic measurements performed on Gd(FeyAl1-y)3 and (GdxY1-x)Fe3 compounds over the temperature range 4.2-1300K were reported.
Abstract: Reports the results of magnetic measurements performed on Gd(FeyAl1-y)3 and (GdxY1-x)Fe3 compounds over the temperature range 4.2-1300K. For x and y>or=0.2 the compounds are ferrimagnetically ordered. In this case, the reciprocal susceptibility chi -1 follows a Neel-type hyperbolic law. The YFe3 compound is ferromagnetic and chi -1 obeys a Curie-Weiss behaviour. Both mean iron moments determined from saturation measurements and Curie constants decrease, but only slowly, by increasing the aluminium or yttrium content. The composition dependence of the iron moments is ascribed to the reduced exchange splittings of Fe 3d states. The electron paramagnetic resonance studies on ferrimagnetic compounds show that the g values and the slope of the linewidth are temperature dependent. The data are analysed in a model which uses the molecular field approximation.
TL;DR: Magnetization measurements as a function of temperature and concentration were performed on single crystals of the formula UAs x Se 1-x. The results were summarized in magnetic phase diagrams as discussed by the authors.
TL;DR: In this article, the magnetization of GdFeB and GdCoB amorphous thin films was studied and it was shown that the Fe moment increases with increasing B concentration beyond a boron to iron ratio of 0.15.
Abstract: Studies have been made of the magnetization of GdFeB and GdCoB amorphous thin films in which ratios of Gd to transition metal and B to transition metal were varied. In GdCoB alloys the Co moment decreases as the sum of the B and Gd concentration increases. Assuming a charge transfer mechanism, each Gd contributes 1.4 electrons and each B 2.1 electrons to the Co 3‐d band. The moment can be described by an additive charge transfer equation. However, in GdFeB alloys the Fe moment increases with increasing B concentration beyond a boron to iron ratio of 0.15. In addition to a reduction in Fe moment by charge transfer of 2.1 electrons from Gd and 2.4 from B, there is an increase in Fe moment due to B addition at higher concentrations. A possible cause for this behavior can be found in the noncollinear (sperimagnetic) alignment of the Fe magnetic sublattice in amorphous ferrimagnetic alloys. High field susceptibility data show that sperimagnetism is reduced with increasing boron.
TL;DR: In this paper, the first observation of an electron spin resonance (ESR) line due to the Mn3O4 impurity in MnO was reported and the temperature dependence of the ESR line was investigated from 20 to 150 K.
Abstract: Here we report the first observation of an electron spin resonance (ESR) line due to the Mn3O4 impurity in MnO. Using this ESR line (g≂2.005, linewidth ΔH≂100 Oe) as a probe, we have shown that Mn3O4 is primarily concentrated on the surface of MnO. The temperature dependence of the ESR line was investigated from 20 to 150 K. Anomalous changes in Hr (resonance field) and ΔH are observed near 42 K, the ferrimagnetic ordering temperature of Mn3O4. Above 42 K, Hr is temperature‐independent, but ΔH shows noticeable changes near 102 and 118 K (TN for MnO). From the observed change in g below 42 K, an anisotropy of 90 Oe for Mn3O4 in MnO is determined and this anisotropy is consistent with the observed ΔH. This anisotropy, about 10−2 times the anisotropy of pure Mn3O4, may be primarily due to exchange anisotropy at the Mn3O4–MnO interface.
TL;DR: In this article, the γ-ray resonance technique has been employed for the study of the magnetic structure of a series of Mn-Zn ferrites, before and after high-temperature annealing.
Abstract: Theγ-ray resonance technique has been employed for the study of the magnetic structure of a series of Mn-Zn ferrites, prepared by a wet chemical method, before and after high-temperature annealing. In agreement with previously reported results, ionic spin relaxation has been observed for the annealed sample Mn0.4 Zn0.6 Fe2 O4. On the other hand, the unannealed sample with the same concentration has shown the existence of superparamagnetic clusters, as proposed by Ishikawa, which exist simultaneously with ferrimagnetic regions in the material. These findings are explained in terms of the magnetic disorder resulting from the particular method of preparation.
TL;DR: In this paper, the Mossbauer spectra have been measured from room temperature to above the Neel temperature for the spinel ferrites Cu1-xNixFe2O4 and Cu 1-xMnxFe 2O4 for x=0.2, 0.4,0.6 and 0.8.
Abstract: The Mossbauer spectra have been recorded from room temperature to above the Neel temperature for the spinel ferrites Cu1-xNixFe2O4 and Cu1-xMnxFe2O4 for x=0.2, 0.4, 0.6 and 0.8. The spectra have been fitted with two sextets in the ferrimagnetic state. Iron is found to be in the trivalent high-spin state. The values of the hyperfine magnetic fields at 57Fe nuclei at A and B sites increase steadily with the increase of Ni concentration. In the case of the Cu1-xMnxFe2O4 series of ferrites they first increase with increase of Mn concentration and then decrease with further increase of Mn concentration. Thus a canted spin structure is expected to be present in the latter ferrites. The quadrupole splitting is zero within experimental error for both the ferrites. The temperature dependence of the hyperfine magnetic field has been determined for all the compositions. The lattice constant decreases with increase of x in the Cu-Ni ferrite whereas it increases with the increase of x in the Cu-Mn ferrite. The Neel temperature increases in Ni concentration whereas it decreases with the increase in Mn concentration.
Patent•
20 Oct 1982
TL;DR: In this paper, a process in which iron (III) oxide hydroxide consisting essentially of lepidocrocite is reduced at from 350° to 600° C. by means of a synthetic polymer with a molecular weight of from 3,000 to 40,000 is described.
Abstract: Acicular ferrimagnetic iron oxides are prepared by a process in which iron (III) oxide hydroxide consisting essentially of lepidocrocite is reduced at from 350° to 600° C. by means of an organic compound which is a synthetic polymer with a molecular weight of from 3,000 to 40,000 to give magnetite, which, if desired, is subsequently partially or completely oxidized with an oxygen-containing gas at from 200° to 450° C.
Patent•
13 Sep 1982
TL;DR: In this article, the authors describe a process making it possible to obtain at least one homogeneous planar magnetization layer in a material constituted by a ferrimagnetic garnet film epitaxied on an amagnetic substrate.
Abstract: The invention relates to a process making it possible to obtain at least one homogeneous planar magnetization layer in a material constituted by a ferrimagnetic garnet film epitaxied on an amagnetic substrate. According to this process, at least one implantation of ions, with the exception of ions of gaseous elements and those of metallic elements occurring in the composition of the solvent is performed in the film at a high dose. The film and substrate are annealed in order to recrystallize in monocrystalline form that part of the film made amorphous by implantation. Application to the production of magnetic bubble memories.
TL;DR: In this article, it was shown that pyrrhotite is a ferrimagnetic semiconductor, and that its magnetic anisotropy is of p type, and the energy gap is ten times smaller along the c axis than in a direction perpendicular to it.
Abstract: We report here measurements on natural crystals of pyrrhotite from room temperature to beyond the Neel point. This material is known as a ferrimagnetic semiconductor, and also for its magnetic anisotropy. The isotherms of the Hall effect are given for samples cut in such a way that the magnetic field is applied along the c axis and perpendicular to it. The sign of the ordinary Hall effect proves that, in the measured temperature region, the conductivity is of p type. The energy gap can be derived from the ordinary Hall effect, and is ten times smaller along the c axis than in a direction perpendicular to it. The spontaneous coefficient Rs falls with increasing temperature, as happens in other antiferromagnetic and ferrimagnetic materials.
TL;DR: In this paper, a spinel pattern superimposed on the MgO was observed, which appeared to be a precursor of the anisotropic ferrimagnetic line, and anisotropy constant and Curie temperature of 258 emu cm−3, −2.7× 10−3 J cm− 3 and 500±10 K, respectively.
Abstract: Single crystals of MgO containing iron in concentrations from 310 to 12900 ppm have been examined by magnetic resonance and reflection electron diffraction before and after ageing in oxygen in the temperature range 600–800° C. Before ageing, only the e.s.r. spectrum of isolated Fe3+ ions in cubic sites was seen and the diffraction patterns revealed MgO alone. After ageing, a strong anisotropic line, centered near g=2.00 and exhibiting the characteristics of ferrimagnetic resonance, was found and its presence was coupled with the appearance of a spinel pattern superimposed on that of the MgO. Analysis of the variation of anisotropy field with ageing time gave estimates of the room-temperature magnetization, first anisotropy constant and Curie temperature of 258 emu cm−3, −2.7× 10−3 J cm−3 and 500±10 K, respectively, which, in view of the close agreement with published data, suggested magnesioferrite formation even at very low iron concentrations. In the initial stages of ageing a strong isotropic resonance line was observed which appeared to be a precursor of the anisotropic ferrimagnetic line.
TL;DR: In this paper, the molar magnetic susceptibility (χm) measurements of heavy rare-earth (RE) molybdates of the type RE2 (MoO4)3 with RE = Gd, Dy, Ho, Er, Tm and Yb are reported in the temperature range 3 to 300 K at a magnetic field of 3.2X105 Am−1.
Abstract: Results of the molar magnetic susceptibility (χm) measurements of heavy rare-earth (RE) molybdates of the type RE2 (MoO4)3 with RE = Gd, Dy, Ho, Er, Tm and Yb are reported in the temperature range 3 to 300 K at a magnetic field of 3.2X105 Am−1. All molybdates show ferrimagnetic behaviour with ferrimagnetic Neel temperatures lying in the range 15 to 24 K. Evaluated magneton numbers agree fairly well with those for free tripositive rare-earth ions. Various magnetic parameters are evaluated using appropriate models.
TL;DR: In this article, the authors provided a direct experimental proof of the correlation between the crystallographic order and the magnetic properties of NiAs-type Fe1−xSe by quenching samples from temperatures high enough to destroy the ordered arrangement.
Abstract: The magnetic structure of NiAs-type Fe1−x
Se is made up by two sets of oppositely aligned ferromagnetic layers parallel to the hexagonal (001) plane. The imbalance of the sublattice magnetizations resulting in ferrimagnetism is usually attributed to the ordered arrangement of the metal vacancies. The results of the present paper provide a direct experimental proof of the correlation between the crystallographic order and the magnetic properties. It could not be distinguished whether the observed effects on the magnetization are due to a combined ordering of vacancies and Fe3+ ions or to the ordering of the Fe3+ ions only. Partial disorder was obtained by quenching samples of Fe0.89Se from temperatures high enough to destroy the ordered arrangement. As inferred from the magnetization data the order parameter varied from 0.83 to 0.47 according to quenching temperatures ranging from 670 K to 1 270 K. In contrast to the magnetization the ferri-antiferromagnetic transformation occurred invariantly at about 170 K irrespective of the different degree of order. The thermoelectric power was positive and increased with decreasing temperature reaching +49µVK−1 at 85 K. The discontinuity observable at about 170 K coincides roughly with the magnetic transformation indicating magnetic contributions to the thermoelectric power.
TL;DR: In this article, the magnetic susceptibilities of rare earth tungstate RE2(WO4)3 (with RE=Ce, Pr, Nd and Gd) are reported in the temperature range 3-300K at a magnetic field of 1.2*106 A m-1.
Abstract: Measurements of magnetic susceptibilities of rare earth tungstates RE2(WO4)3 (with RE=Ce, Pr, Nd and Gd) are reported in the temperature range 3-300K at a magnetic field of 1.2*106 A m-1. All the tungstates are found to be ferrimagnetic with ferrimagnetic Neel temperature lying in the range 20-30K (30K (Ce), 25K (Pr), 20K (Nd) and 20K (Gd)). Values of effective magneton numbers agree fairly well with those of free tripositive rare earth ions. The results are discussed on the basis of a newly proposed model.
01 Oct 1982
TL;DR: In this article, the existence of high field magnetic susceptibility at low temperature for samples with x≧0.4 has been interpreted in terms of noncollinear ferrimagnetic arrangements.
Abstract: By means of paramagnetic Mossbauer spectra the cation distribution of the solid solution CoFe
x
Al2−x
O4 with 0≦x≦1.5 has been determined. The existence of high field magnetic susceptibility at low temperature for samples with x≧0.4 has been interpreted in terms of non-collinear ferrimagnetic arrangements. Below the Neel temperature the spinel CoAl2O4 has a complex antiferromagnetic behavior.
TL;DR: In this article, the dependence of spontaneous magnetostriction on Co concentration was estimated taking into account Vegard's rule and the thermal expansion of Dy2Fe17, showing that these compounds exhibit a larger specific volume in the ferrimagnetic than in the paramagnetic state.
TL;DR: In this paper, the crystal and magnetic properties of Dy6Fe23 intermetallic compound were investigated by X-ray, magnetometric and Mossbauer effect methods, and the Curie temperature and the compensation temperature were determined to be 536 K and 273 K respectively.
Abstract: The crystal and magnetic properties of the Dy6Fe23 intermetallic compound were investigated by X-ray, magnetometric and Mossbauer effect methods. The Dy6Fe23 phase is a ferrimagnet with a Th6Mn23-type crystal structure. The iron and dysprosium sublattices are coupled antiferromagnetically. The Curie temperature and the compensation temperature were determined to be 536 K and 273 K respectively. The low temperature 57Fe Mossbauer absorption spectra indicate that more than five magnetically non-equivalent crystal sites are occupied by iron atoms. The hyperfine interaction parameters were derived from both the 57Fe and the 161Dy Mossbauer absorption spectra. The Mossbauer effect measurements under a high external magnetic field indicate the existence of non-collinear ordering in the iron sublattices of the compound.
TL;DR: In this article, the role of the exchange striction energy in ferrimagnetic materials was investigated and a relation between the exchange strain energy and the volume anomaly was deduced from molecular field theory and is confronted with experiment.
Abstract: The role of the exchange striction energy in ferrimagnetic materials is reported: (a) A relation between the exchange striction ’’volume anomaly’’ ΔV/V and the sublattice magnetizations is deduced from molecular field theory and is confronted with experiment. (b) A relation between the magnetoelastic anisotropy term ΔK specific to the polycrystalline state and the product of the exchange stresses by the magnetostrictive strain is established from experiment, on the basis of a previously proposed mechanism. (c) A relation between the crystal lattice parameter a and the magnetization states in magnetic domains and domain walls is proposed.
Patent•
13 Apr 1982
TL;DR: In this paper, the authors proposed to improve the peak electric power resistance characteristics of a phase shifter by covering a package part in a waveguide for a conductor, used for controlling the magnetization state of a ferrimagnetic material, with an insulator having high dielectric strength.
Abstract: PURPOSE:To improve the peak electric power resistance characteristics of a phase shifter by covering a package part in a waveguide for a conductor, used for controlling the magnetization state of a ferrimagnetic material, with an insulator having high dielectric strength. CONSTITUTION:A ferrimagnetic material 2 is provided in contact with the upper and lower walls of a waveguide 1, and in this ferrimagnetic material 2, a hole 3 wherein a conductor 4 covered with an insulator 5 of silicon rubber, etc. having high dielectric strength runs is made. When an impulsive current flows through the conductor 4, magnetism surrounding the hole 3 resides in the ferrimagnetic material 2, and causes a circular polarization magnetic field, passing in the waveguide 1, to shift in transmission phase by a prescribed extent. During high peak electric power operation, an intense high-frequency electric field converges to the ferrimagnetic material 2, but the resulting discharging of the conductor 4 is prevented by the high-dielectric-strength insulator 5, thereby greatly improving electric power which causes the breaking of the conductor 4.