Spin-phonon coupling in BaFe12O19 M-type hexaferrite

Júnior, Flávio M. Silva; Paschoal, C. W. A.

doi:10.1063/1.4904062

Cited by 27 publications

(7 citation statements)

References 25 publications

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“…The bands at 164 and 178 cm −1 are assigned to the motion of the spinel block as a whole [35]. The band near 673 cm −1 is not usually noted in barioferrite spectra [35,37]; it was observed once in the spectrum of pure barioferrite [38], and it is possible, that this band is related to Fe 3+ in the bipyramid. 1c.…”

Section: Chemical Composition and Raman Spectroscopymentioning

confidence: 94%

“…The detector was vertically translated by 67 mm to increase the maximum resolution to 0.67 Å. The X-ray diffraction data were collected from a single crystal mounted onto the multi-axis PRIGo goniometer [37] using the DA+ acquisition software [38]. Data were collected at the 0.7085 Å wavelength with 0.1 s exposure time and 0.1 • oscillation range using a focused 80 × 45 μm (h × v) beam.…”

Section: Methodsmentioning

confidence: 99%

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New Mineral Species and Their Crystal Structures

Pekov¹,

Galuskina²

2019

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The discovery of any new mineral is a significant event in fundamental science. It enriches mineralogy and geology as well as crystallography, solid-state physics, and chemistry. Some new minerals are interesting for material science and engineering due to their useful physical properties.The number of discoveries of new mineral species is the one of the most important quantitative parameters of success in mineralogical science. The USA and Russia are at present the record-holders in the number of new mineral found: About eight hundred mineral species have been discovered on the territories of each of these two countries. Italy and Germany (350 each) are next, followed by Canada (230), Sweden (183), Australia (162), Japan (143), Chile (133), China (132), the Czech Republic (127), Great Britain (126), France (119), and Namibia ( 104), which have also made significant contributions to world mineralogy. This Special Issue of Minerals is devoted to new mineral species and their crystal structures.Fourteen articles were published therein. We are very thankful to all authors, who published the data of their recent investigations in this issue.All articles were carefully reviewed by experts in mineralogy and crystallography. We are grateful to all reviewers who found the time to help to improve the submitted manuscripts. Further, of course, we would like to express our deepeset appreciation to the staff of Minerals, as well support staff, for the big and necessary work on all stages of the manuscript preparation for production.

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Section: Chemical Composition and Raman Spectroscopymentioning

confidence: 94%

Section: Methodsmentioning

confidence: 99%

New Mineral Species and Their Crystal Structures

Pekov¹,

Galuskina²

2019

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“…Being planar, self-biased and low-loss materials, hexaferrites meet the requirements of modern microwave and THz circulators, phase-shifters, filters, isolators and millimeter wave resonators antennas 15,16,30,52 . The fact that these compounds are considered nowadays as one of the most promising material classes for telecommunication systems has been clearly demonstrated in a recent work [42] . Here, BaFe 12 O 19 /polydimethylsiloxane nanocomposite that exhibits a zero-bias (no external magnetic field) ferromagnetic resonance frequency at 46.6 GHz is proposed for the design of a circulator with operating frequency of 35 GHz.…”

Section: Conclusion and Prospectsmentioning

confidence: 97%

“…Such complexity can make the soft mode couple to the magnetic subsystem (the possibility of spin-phonon coupling in hexaferrites has been reported in, e.g. 9,[42][43][44][45][46] ). Also, we cannot exclude a coupling between the soft mode and the transitions within fine-structure components of the 5 E ground state of tetrahedrally coordinated Fe 2+ , since the frequencies of both types of excitations are close or even overlap, as discussed above (see Fig.…”

Section: 36mentioning

confidence: 99%

Lead-substituted barium hexaferrite for tunable terahertz optoelectronics

Alyabyeva

Prokhorov

Винник

et al. 2021

Preprint

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In recent years, due to their outstanding dielectric and magnetic properties, hexagonal ferrites (hexaferrites) have attracted considerable interest for developing electronic components of next-generation communication systems. The complex crystal structure of hexaferrites and critical dependences of their electric and magnetic properties on external factors, like magnetic or electric fields, pressure or doping, open ample opportunities for targeted tuning of these properties when designing specific devices. To that end, we explored the electromagnetic properties of the Pb-substituted barium hexaferrite, Ba1-xPbxFe12O19, a compound featuring an extremely rich set of physical phenomena that are inherent in the dielectric and magnetic subsystems of the material and are expected to have significant effect on its electromagnetic response at radio and terahertz frequencies. We performed the first detailed measurements of the AC response of single-crystalline Ba1-xPbxFe12O19 in an extremely broad spectral range from 1 Hz to 240 THz down to temperatures as low as 5 K. We fully characterized numerous microscopic phenomena that determine the broad-band dielectric response of the compound, and we analyzed their nature. This includes temperature-activated radiofrequency relaxations that were attributed to the dynamic response of magnetic/dielectric domains. The terahertz response is dominated by a ferroelectric-like soft mode with an unusual temperature behavior that we explain by means of a microscopic model. Several narrower terahertz excitations are associated with electronic transitions between the fine-structure components of the Fe2+ground state. Narrow resonances detected in the gigahertz region are presumably of magneto-electric origin. The obtained data on diverse but controllable electromagnetic properties of Ba1-xPbxFe12O19 compounds provides the researchers with information that makes the entire class of hexaferrites materials attractive for manufacturing electronic devices for the radiofrequency and terahertz ranges, such as absorbing coatings, anti-reflective coatings, absorbers, electromagnetic shields, antennas, phase shifters, filters, resonators, modulators, etc.

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Section: Chemical Composition and Raman Spectroscopymentioning

confidence: 99%

Dynamic Disorder of Fe3+ Ions in the Crystal Structure of Natural Barioferrite

et al. 2018

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A natural barioferrite, BaFe3+12O19, from a larnite–schorlomite–gehlenite vein of paralava within gehlenite hornfels of the Hatrurim Complex at Har Parsa, Negev Desert, Israel, was investigated by Raman spectroscopy, electron probe microanalysis, and single-crystal X-ray analyses acquired over the temperature range of 100–400 K. The crystals are up to 0.3 mm × 0.1 mm in size and form intergrowths with hematite, magnesioferrite, khesinite, and harmunite. The empirical formula of the barioferrite investigated is as follows: (Ba0.85Ca0.12Sr0.03)∑1(Fe3+10.72Al0.46Ti4+0.41Mg0.15Cu2+0.09Ca0.08Zn0.04Mn2+0.03Si0.01)∑11.99O19. The strongest bands in the Raman spectrum are as follows: 712, 682, 617, 515, 406, and 328 cm−1. The structure of natural barioferrite (P63/mmc, a = 5.8901(2) Å, c = 23.1235(6) Å, V = 694.75(4) Å3, Z = 2) is identical with the structure of synthetic barium ferrite and can be described as an interstratification of two fundamental blocks: spinel-like S-modules with a cubic stacking sequence and R-modules that have hexagonal stacking. The displacement ellipsoids of the trigonal bipyramidal site show elongation along the [001] direction during heating. As a function of temperature, the mean apical Fe–O bond lengths increase, whereas the equatorial bond lengths decrease, which indicates dynamic disorder at the Fe2 site.

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Spin-phonon coupling in BaFe12O19 M-type hexaferrite

Cited by 27 publications

References 25 publications

New Mineral Species and Their Crystal Structures

New Mineral Species and Their Crystal Structures

Lead-substituted barium hexaferrite for tunable terahertz optoelectronics

Dynamic Disorder of Fe3+ Ions in the Crystal Structure of Natural Barioferrite

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