A Dy-based single ion magnet in a SrLaGaO matrix: enhanced parameters in an expanded crystal lattice.

Dy doped SrLaGaO exhibits unusually slow relaxation of magnetization determined by two widely separated excited Kramers doublets with a second remagnetization energy barrier of 223 cm. This value considerably exceeds that for analogous Ca(Y,Dy)AlO in spite of the apparently enlarged Dy coordination sphere.

An ultra-high-entropy rare earth orthoferrite (UHE REO): solution combustion synthesis, structural features and ferrimagnetic behavior.

A novel ultra-high-entropy rare earth orthoferrite (UHE REO) of ScYLaCePrNdSmEuGdTbDyHoErTmYbLuFeO nominal composition was successfully synthesized for the first time through a simple and efficient solution combustion approach. PXRD, Raman, and Fe Mössbauer spectroscopy confirmed the high chemical and phase purity of the synthesized UHE REO (hereafter denoted as ΣREFeO), which belonged to the space group, typical of the perovskite-like rare earth orthoferrites. Despite the fact that the main X-ray reflections, vibration modes, and spectral Mössbauer components unambiguously indicate the single-phase nature of the sample, the results of SEM and TEM make it possible to establish the presence of a main (about 50 nm) and a minor ultrafine (about 10 nm) fraction of ΣREFeO nanoparticles.

Dy single ion magnet in the extended inorganic solid Ca(Y,Dy)AlO.

The first instance of a rare-earth single-ion magnet in a robust extended solid has been found, which possesses a crystal structure different from apatite. The compound exhibits slow relaxation of magnetization in a zero field revealing simultaneously two energy barriers for magnetization reversal.

Correction: High-coercivity hexaferrite ceramics featuring sub-terahertz ferromagnetic resonance.

Correction for 'High-coercivity hexaferrite ceramics featuring sub-terahertz ferromagnetic resonance' by Evgeny A. Gorbachev , , 2022, , 1264-1272, DOI: https://doi.org/10.

High-coercivity hexaferrite ceramics featuring sub-terahertz ferromagnetic resonance.

Herein, we demonstrate for the first time compact ferrite ceramics with giant coercivity. The materials are manufactured sintering single-domain SrCaFeAlO particles synthesized by a citrate-nitrate auto-combustion method. The obtained ceramics show coercivities up to 22.

Sandwiched CoFeO/SrFeAlO/CoFeO nanoparticles with exchange-coupling effect.

Exchange-coupled hard/soft ferrite nanoparticles are prospective to squeeze out a part of expensive magnets based on rare-earth elements. However, the known exchange-coupled composite ferrite nanoparticles often suffer from the lack of a powerful enough hard magnetic core, high defectivity of magnetic phases, and a poor interface between them. Herein, we demonstrate the first efficient synthesis of sandwiched nanomagnets, which exhibit a pronounced exchange-coupling effect.

Glass-Ceramic Synthesis of Cr-Substituted Strontium Hexaferrite Nanoparticles with Enhanced Coercivity.

Magnetically hard ferrites attract considerable interest due to their ability to maintain a high coercivity of nanosized particles and therefore show promising applications as nanomagnets ranging from magnetic recording to biomedicine. Herein, we report an approach to prepare nonsintered single-domain nanoparticles of chromium-substituted hexaferrite via crystallization of glass in the system SrO-FeO-CrO-BO. We have observed a formation of plate-like hexaferrite nanoparticles with diameters changing from 20 to 190 nm depending on the annealing temperature.

Tb-based silicate apatites showing slow magnetization relaxation with identical parameters for the Tb and Dy counter ions.

Tb-diluted and Tb-rich apatite-type silicates with compositions YTbCa(SiO)O and TbCa(SiO)O, respectively, exhibit field induced multiple slow relaxation of magnetization. The former reveals two slow relaxation paths, the latter only one with a longer relaxation time of several seconds. The relaxation features of the Tb-diluted one are comparable with those of analogue compounds, where Tb is replaced by Dy, as well as with those of a Tb-doped calcium phosphate apatite.

Dysprosium magnesium silicate apatite featuring field and temperature stable slow magnetization relaxation.

Dy-Mg silicate DyMg(SiO)O has been prepared by high-temperature solid state reaction. It has an apatite type structure (6/) with the Dy atoms fully occupying the 6h site and being in random distribution with the Mg atoms at the 4f site. The compound reveals dual magnetization relaxation with widely varying contributions from fast (FR) and slow (SR) relaxation paths controlled by field and temperature.

All-Inorganic Single-Ion Magnets in Ceramic Matrices.

All-inorganic single-ion magnets representing paramagnetic ions incorporated in a crystalline diamagnetic matrix are reviewed. Key results and advantages of this approach in comparison with the common strategy based on molecular metal-organic complexes are considered, and some unsolved problems and future perspectives are discussed.

Multiple slow relaxation of magnetization in Dy confined in the crystal matrix of rare-earth-calcium silicates with the apatite structure.

Apatite-type silicates Y7.75Dy0.25Ca2(SiO4)6O2 and Dy8Ca2(SiO4)6O2 were prepared by high-temperature solid state synthesis.

TbO in a calcium apatite matrix featuring a triple trigger-type relaxation of magnetization.

Tb for Ca substituted hydroxyapatite ceramic samples with composition Ca10-xTbx(PO4)6(OH1-x/2-δ)2, where x = 0.1, 0.5, were synthesized by solid-state reaction at 1300 °C in air, and their crystal structure, vibrational spectra, luminescence, and magnetic properties were studied.

Slow Spin Relaxation in Dioxocobaltate(II) Anions Embedded in the Lattice of Calcium Hydroxyapatite.

Pure-phase cobalt-doped calcium hydroxyapatite ceramic samples with composition Ca(PO)[(CoO)(OH)], where x = 0-0.2, were synthesized by high-temperature solid-state reaction, and their crystal structures, vibrational spectra, and magnetic properties were studied. Co atoms are found to enter into the apatite trigonal channel formally substituting H atoms and forming bent dioxocobaltate(II) anions.

"Isolated" DyO Embedded in a Ceramic Apatite Matrix Featuring Single-Molecule Magnet Behavior with a High Energy Barrier for Magnetization Relaxation.

Meeting the challenges of Moore's Law, predicting ambitious miniaturization rates of integrated circuits, requires to go beyond the traditional top-down approaches, and to employ synthetic chemistry methods, to use bottom-up techniques. During the recent decades, it has been shown that open-shell coordination compounds may exhibit intramolecular spontaneous magnetization, thus offering promising prospects for storage and processing of digital information. Against this background we regarded it rewarding to implement similar magnetic centers into a ceramic material, which would provide better long-term mechanical and chemical durability.

A Co-based single-molecule magnet confined in a barium phosphate apatite matrix with a high energy barrier for magnetization relaxation.

An apatite-type barium phosphate with a high content of cobalt ions in the trigonal channels features slow relaxation of magnetization with an energy barrier U of up to 387 cm, which is well above the values for all so far known d-metal based single-molecule magnets (SMMs).

Cobalt-Based Single-Ion Magnets on an Apatite Lattice: Toward Patterned Arrays for Magnetic Memories.

Single-ion magnets (SIMs) that can maintain magnetization direction on an individual transition metal atom represent the smallest atomic-scale units for future magnetic data storage devices and molecular electronics. Here we present a robust extended inorganic solid hosting efficient SIM centers, as an alternative to molecular SIM crystals. We show that unique dioxocobaltate(II) ions, confined in the channels of strontium hydroxyapatite, exhibit classical SIM features with a large energy barrier for magnetization reversal (U) of 51-59 cm.

Stable colloidal solutions of strontium hexaferrite hard magnetic nanoparticles.

Herein we demonstrate an approach to prepare a colloidal solution of strontium hexaferrite via a glass-ceramic route. The as obtained colloids are stable and resistive to aggregation or sedimentation. They reveal outstanding magnetic and magneto-optical properties because of their platelet-like anisotropic shape and high permanent magnetic moment.

Rich diversity of single-ion magnet features in the linear OCu(III)O(-) ion confined in the hexagonal channels of alkaline-earth phosphate apatites.

Following our recent discovery of slow spin relaxation in the unique [OCu(III)O](-) anion located in the apatite-type pigment A10(PO4)6(CuxOH1-x-y)2, where A = Sr, we present the magnetic behavior of this anion for the cases of A = Ca and Ba, which provides evidence for a cation field impact on the properties of a single-ion magnet molecular anion.

Identification of the chromophore in the apatite pigment [Sr10(PO4)6(Cu(x)OH(1-x-y))2]: linear OCuO- featuring a resonance Raman effect, an extreme magnetic anisotropy, and slow spin relaxation.

A new chromophore has been identified in copper-doped apatite pigments having the general composition [Sr(10)(PO(4))(6)(Cu(x)OH(1-x-y))(2)], in which x=0.1, 0.3 and y=0.

On the origin of near-IR luminescence in Bi-doped materials (II). Subvalent monocation Bi⁺ and cluster Bi₅³⁺ luminescence in AlCl₃/ZnCl₂/BiCl₃ chloride glass.

Broadband NIR photoluminescence (from 1000 to 2500 nm) was observed from partially reduced AlCl₃/ZnCl₂/BiCl₃ glass, containing subvalent bismuth species. The luminescence consists of three bands, assigned to Bi⁺ , Bi₂⁴⁺, and Bi₅³⁺ ions. The physical and optical characteristics of these centers and possible contribution to NIR luminescence from bismuth-doped oxide glasses are discussed.

Controlled way to prepare quasi-1D nanostructures with complex chemical composition in porous anodic alumina.

Herein we propose a novel approach to the preparation of quasi-1D nanostructures with various chemical compositions based on infiltration of colloidal solution into the asymmetric anodic alumina membrane. The proposed technique was successfully applied for the preparation of ordered arrays of the magnetically hard anisotropic hexaferrite nanostructures.