Yb Compounds Research Articles

Potassium, ytterbium(II), and samarium(III) alkoxide complexes containing the <i>tris</i>((2-dimethylaminomethyl)phenyl)methoxide ligand: synthesis and structures

The reaction oftris((2-dimethylaminomethyl)phenyl)methanol ((2-Me2NCH2C6H4)3COH) with potassium hydride in THF at –35°C affords dimeric alkoxide {[(2-Me2NCH2C6H4)3CO]K(THF)}2(I) in a yield of 90%. The reaction of compound I with YbI2(THF)2(1 : 1, 25°C) gives the Yb(II) alkoxyiodide complex {[(2-Me2NCH2C6H4)3CO]Yb(μ-I)(THF)2}2(II) in a yield of 57%. Complex II in the crystalline state is dimeric due to two bridging iodide ligands. Unlike the Yb(II) compound, the exchange reaction of complex I with SmI2(THF)2 (1 : 1, 25°C) in THF followed by the addition of dimethoxyethane (DME) involves the oxidation of the metal to form the trivalent samarium complex [(2-Me2NCH2C6H4)3CO]2SmI (III), which is isolated in a yield of 60%. The molecular structures of the complexes are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2259700 (I), 2259701 (II), and 2259702 (III)).

Photoluminescence of CaGa2S4: Nd, Yb compound at room temperature

In this paper, CaGa2S4:3%Nd,5%Yb; CaGa2S4:5%Yb; CaGa2S4:3%Nd compounds were synthesized, and their photoluminescence (PL) spectra, PL excitation (PLE) spectra and PL decay properties were studied at room temperature under one-photon and multi-photon excitation in a wide range of excitation intensities. The synthesis of the CaGa2S4 compound was carried out by a solid-phase reaction of a stoichiometric mixture of CaS and Ga2S3 powders in a quartz ampoule. Yb and Nd doping was carried out during the synthesis process using YbF3 and NdF3. PLE spectra were studied in the wavelength range from 250 to 850 nm, and PL spectra in the range of 400–1500 nm. It has been shown that after introducing Yb3+ ions into thiogallate crystals with Nd3+ ions, a new band near 488 nm is formed and the PL intensity increases by 1–2 orders of magnitude. The anti-Stokes PL spectra of CaGa2S4: Nd, Yb crystals in the visible region of the spectrum (400–700 nm) were studied when excited by continuous wave laser radiation with a wavelength of 975 nm. The kinetics of PL decay of all types of compounds at different wavelengths of single- and multi-photon excitation were determined. Depending on the PLE conditions, wavelength and intensity of the exciting radiation, monoexponential and non-monoexponential decay kinetics were observed with decay times in the range of 20–90 μs. Possible mechanisms of PLE and PL of CaGa2S4 crystals doped with neodymium and ytterbium ions are discussed.

Gold(I) {2}‐Metallacoronates derived from a Catechol‐scaffolding Aroylbis(N,N‐diethylthiourea): Syntheses and Structures

AbstractOne‐pot reactions of catechol‐scaffolding aroylbis(N,N‐diethylthiourea) H2Lcat and mixtures of lanthanide nitrates Ln(NO3)3 (Ln3+=La3+, Nd3+ or Yb3+) or indium(III) chloride InCl3 and [Au(tht)Cl] in methanol in the presence of the supporting base Et3N result in gold(I) {2}‐metallacoronates. Depending on radii of the trivalent metal ions, the corresponding complexes are separated either in the neutral form with the composition {(NO3‐κ2‐O,O’)Ln⊂[Au2(Lcat)2]} in the cases of La3+ and Nd3+ or as the ‘ion‐pair’ {Yb⊂[Au2(Lcat)2]}+(NO3)− for the Yb(III) compound. The cationic complexes can be isolated in higher yields as the PF6− salts {M⊂[Au2(Lcat)2]}+(PF6)− (M3+=Yb3+ or In3+) by treatment of reaction mixtures with (n‐Bu4N)(PF6).

Er-driven incommensurate to commensurate magnetic phase transition of Fe in the spin-chain compound BaErFeO4

Magnetic phase transitions and structures of the spin-chain compound BaErFeO4 were investigated by measurements of magnetic properties (specific heat, magnetic susceptibility) and neutron diffraction. The lattice geometry of the orthorhombic crystal structure (space group ) of the BaRFeO4 compounds (R=Dy–Yb, Y) supports frustrations which lead to multiple magnetic phase transitions with complex magnetic structures. BaErFeO4 undergoes three successive magnetic phase transitions at TN1=49K, TN2=33.4K, and TN3=3.4K. In contrast with the previously investigated BaRFeO4 (R=Y, Tm, Yb) compounds, all with incommensurate magnetic propagation vectors k1=(0,0,kz), BaErFeO4 is the first member in this series that shows a phase transition from an incommensurate (k1 below TN1) to a commensurate magnetic structure with k2=(12,0,12) below TN2. In the crystal structure, all magnetic ions (Fe1, Fe2, Er1, and Er2) are part of chains propagating along the b axis. Below TN1, strong antiferromagnetic (AFM) Fe-Fe spin-exchange coupling between square pyramidal (Fe1) and octahedral (Fe2) centers generates a collinear AFM structure with a constant size of the ordered Fe moments and a constant magnetic phase inside each chain of Fe3+ cations. Exchange coupling between the Fe chains is much weaker. At TN2, 3d−4f exchange interactions induce an ordered moment at the Er3+ ions, which results in a change of the direction of the ordered Fe moments from the b direction (above TN2) to inside the ac plane (below TN2) and a change from an incommensurate (k1 above TN2) to a commensurate (k2 below TN2) AFM structure. Toward lower temperature, 4f−4f exchange interactions become stronger and create at TN3 a constant magnetic phase inside each chain of Er3+ cations. At TN2 and TN3, the magnetic susceptibility shows sharp decreases that coincide with large increases of the correlation length of the magnetic structure. The unique magnetic structures of BaErFeO4 are compared with those of other BaRFeO4 compounds by considering experimental and theoretical aspects. ©2024 American Physical Society 2024 American Physical Society

Elucidating ultranarrow 2F7/2 to 2F5/2 absorption in ytterbium(iii) complexes.

Achieving ultranarrow absorption linewidths in the condensed phase enables optical state preparation of specific non-thermal states, a prerequisite for quantum-enabled technologies. The 4f orbitals of lanthanide(iii) complexes are often referred to as "atom-like," reflecting their isolated nature, and are promising substrates for the optical preparation of specific quantum states. To better understand the photophysical properties of 4f states and assess their potential for quantum applications, theoretical building blocks are required for rapid screening. In this study, an atomic-level perturbative calculation (i.e., spin-orbit crystal field, SOCF) is applied to various Yb(iii) complexes to investigate their linear absorption and emission through a fitting mechanism of their experimentally determined transition energies and oscillator strengths. In particular, the optical properties of (thiolfan)YbCl(THF) (thiolfan = 1,1'-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene), a recently reported complex with an ultranarrow optical linewidth, are computed and compared to those of other Yb(iii) compounds. Through a transition energy sampling study, major contributors to the optical linewidth are identified. We observe particularly isolated f-f transitions and narrow linewidths, which we attribute to two distinct factors. Firstly, the ultra-high atomic similarity of the orbitals involved in the optical transition, along with the presence of an anisotropic crystal field, collectively contribute to the observed narrow transitions. Secondly, we note highly correlated excited-ground energy fluctuations that serve to greatly suppress inhomogeneous line-broadening. This article illustrates how SOCF can be used as a low-cost method to probe the influence of crystal field environment on the optical properties of Yb(iii) complexes to assist the development of novel lanthanide series quantum materials.

Study of the d-f magnetic interaction in V-doped RCrO4 (R[dbnd]Tb, Dy, Er and Yb) compounds

In this work, we have carried out a detailed study of the structural and magnetic properties of RVxCr1−xO4 (RTb, Dy, Er, and Yb; x = 0.0, 0.3, 0.5, 0.7 and 1.0) compounds obtained by the co-precipitation method. X-ray diffraction data using Rietveld refinement shows that all samples present a single phase consistent with the zircon-type structure (I41/amd space group (No. 141)). The lattice parameter changes as a function of both V-concentration and the rare earth ion. The analyses on T-dependent magnetic susceptibility indicate that RCrO4 samples are ferromagnetic while RVxCr1−xO4 ones are antiferromagnetic for x = 0.7 and 1.0. The increase of magnetic transition temperatures from 3 K (RVO4) to 20 K (RCrO4) can be an indicator that the R–Cr magnetic interaction takes an important role in the magnetic properties in these compounds. Isothermal magnetization curves measured at T = 2 K for all samples reinforce the ferromagnetic character of RCrO4 samples once they present remanence, coercivity, and magnetization saturation. However, the fact that the expected gJJ value for the full multiplet is not reached for all samples must be associated with the crystal electric field on the rare earth ion.

Ytterbium 10-carboxyperylene-3,4,9-tricarboxylates for targeted NIR luminescent bioimaging.

Two new ytterbium coordination compounds Yb(HPTC)(H2O)2 (Yb1) and Yb(HPTC)(Phen) (Yb2) were obtained using 10-carboxyperylene-3,4,9-tricarboxylate ion (HPTC3-) as a sensitizer. Both coordination compounds exhibited intense NIR-II luminescence upon excitation in the visible range and formed stable suspensions with nanoparticles of 50-70 nm in size in an aqueous solution of sodium alginate. Both complexes demonstrated non-toxicity up to at least 25 mg L-1 in two cell cultures: cancer cells MCF7 and embryonic cells HEK293T - making them suitable for bioimaging. For both complexes, the accumulation in cells was directly measured and it was shown that the accumulation of Yb2 was the same for both cell types (0.51-0.52 πg per cell), while Yb1 demonstrated selective accumulation in cancer cells (0.04 πg per cell for HEK293T and 7.00 πg per cell for MCF7). Thus, Yb1 can also be proposed as a selective vis-excited NIR emitting bioprobe.

Suppression of Geometrical Frustration in Defective Yb Triangular Lattice Compounds Yb2Cu2nSn+3 with n = 2.2 and 3.6

Suppression of Geometrical Frustration in Defective Yb Triangular Lattice Compounds Yb₂Cu_2nS_n+3 with n = 2.2 and 3.6

Stabilization Of The CN3 5- Anion In Recoverable High-pressure Ln3 O2 (CN3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) Oxoguanidinates.

A series of isostructural Ln3 O2 (CN3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high-pressure (25-54 GPa) high-temperature (2000-3000 K) conditions in laser-heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single-crystal X-ray diffraction (SCXRD) as well as corroborated by X-ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln3 O2 (CN3 ) solids are composed of the hitherto unknown CN3 5- guanidinate anion-deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln3 O2 (CN3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln3 O2 (CN3 ) compounds are recoverable to ambient conditions. The stabilization of the CN3 5- guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.

Stabilization Of The CN35− Anion In Recoverable High‐pressure Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) Oxoguanidinates

AbstractA series of isostructural Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high‐pressure (25–54 GPa) high‐temperature (2000–3000 K) conditions in laser‐heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single‐crystal X‐ray diffraction (SCXRD) as well as corroborated by X‐ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln3O2(CN3) solids are composed of the hitherto unknown CN35− guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln3O2(CN3) compounds are recoverable to ambient conditions. The stabilization of the CN35− guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.

Electronic structure of YbFe4Al8 antiferromagnet: A combined X-ray photoelectron spectroscopy and first-principles study

Depending on their chemical composition, Yb compounds often exhibit different valence states. Here we investigate the valence state of YbFe4Al8 using X-ray photoelectron spectroscopy (XPS) and first-principles calculations. The XPS valence band of YbFe4Al8 consists of two contributions coming from divalent (Yb2+) and trivalent (Yb3+) configurations. The determined value of the valence at room temperature is 2.81. Divalent and trivalent contributions are also observed for core-level Yb 4d XPS spectra. We study several collinear antiferromagnetic models of YbFe4Al8 from the first-principles and for comparison we also consider LuFe4Al8 with a fully filled 4f shell. We predict that only Fe sublattices of YbFe4Al8 carry significant magnetic moments and that the most stable magnetic configuration is AFM-C with antiparallel columns of magnetic moments. We also present a Mulliken electronic population analysis describing charge transfer both within and between atoms. In addition, we also study the effect of intra-atomic Coulomb U repulsion term applied for 4f orbitals on Yb valence and Fe magnetic moments.

Novel ytterbium Schiff base complex: Toward efficient solution-processed NIR-emitting OLED

Lanthanide complexes Ln(L)(HL) (H 2 L = 2-tosylamino-benzylidene-(2-benzo[d]thiazole) hydrazone; Ln = Yb, Gd) were obtained and thoroughly characterized. The monomeric structure of Yb(L)(HL)·Solv 1 (Solv 1 = 2CH 3 CN + 2EtOH + H 2 O) and the ligand structure were determined by single crystal X-ray diffraction data. Relatively high solubility (ca. 5 g/l) and quantum yield (0,9%), as well as mobility of electrons (2,33·10 −6 cm 2 /V·s) and holes (4,94·10 −7 cm 2 /V·s) of Yb(L)(HL) allowed its successful use as a host-free near-infrared OLED emission layer. OLED with the heterostructure ITO/PEDOT:PSS/poly-TPD/Yb(L)(HL)/OXD-7/LiF/Al demonstrated pure 1000 nm centred near-infrared luminescence with the external quantum efficiency up to 0.025%, which is one of the highest value for 1000 nm centred electroluminescence. • Ytterbium coordination compound Yb(L)(HL)·Solv with 2-tosylamino-benzylidene-(2-benzo[d]thiazole) hydrazone was obtained. • Crystal structures of the complex and the new ligand were determined. • Yb(L)(HL)·Solv demonstrate ytterbium luminescence with the quantum yield up to 0,9% and high solubility. • Mobility of charge carriers was measured (2,33·10 −6 cm 2 /V·s and 4,94·10 −7 cm 2 /V·s for electrons and holes). • Yb(L)(HL)·-based solution-processed host-free OLED demonstrated the pure 1000 nm centred NIR emission at low voltages.

Synthesis and flux-growth of rare-earth magnesium pentaborate crystals RMgB5O10 (R = Y, Gd, La, Tm and Yb)

For the first time, to our knowledge, RMgB5O10 (R = Tm, Yb) compounds have been synthesized by solid-phase synthesis. For RMgB5O10 (R = Y, La, Gd) the growth conditions are optimized in the temperature range 1000 – 800 °C by the flux method with a change in the concentration of the crystal-forming component vs the concentration of the solvent in the initial load. Using the data obtained the RMgB5O10 single crystals with optical quality and dimensions up to 20 mm × 20 mm × 10 mm co-activated with erbium, ytterbium, and neodymium were growth by the solution growth from dipped seed (SGDS) method. (Er,Yb):RMgB5O10 in general have characteristics similar to the previously studied laser crystals of huntite-type borates (Er,Yb):RAl3(BO3)4 (R = Y, Gd, Lu) and appear to be an alternative material due to a simpler growing and processing technology.

高圧力下のCe, Yb化合物における<i>f</i>電子混成状態と光学伝導度

高圧力下のCe, Yb化合物における<i>f</i>電子混成状態と光学伝導度

Cationic variation for LnAl2Si2 (Ln = Y, Sm, Tb, Dy, Yb) compounds by density functional theory

Detailed Cationic variation for LnAl2Si2 (Ln = Y, Sm, Tb, Dy, Yb) compounds have been discussed under the frame work of density functional theory (DFT). Our reported optimized theoretical lattice constants for the studied material are in good agreement with experimental measurements and we also find that ferromagnetic phase is more stabilize and acceptable in comparison with Nonmagnetic phase. The calculated band structures and density of state (DOS) of LnAl2Si2 show metallic nature due to the overlapping and crossing mechanisms of minima of conduction band (CB) and maxima valance band (VB) across the Fermi level as well as strong hybridization of Y d and Sm/Tb/Dy/Yb f states with (Al, Si) p states in both spin configurations. Lastly, the investigation of magnetic properties defines a strong metallic behavior for all these understudy ferromagnetic compounds. These result shows that the ternary lanthanide based aluminum silicides are likely encouraging candidates for advance future magnetic applications especially in the vast area of spintronics.

Unconventional magnetic order emerging from competing energy scales in the new RRh3Si7 intermetallics ( R = Gd-Yb)

The competition between Ruderman-Kittel-Kasuya-Yosida (RKKY), crystal electric field (CEF), and Kondo energy scales has recently emerged at the heart of complex magnetism in several Ce- or Yb-based intermetallics. Hard axis magnetic order has been observed in a handful of these compounds, independent of the crystal symmetry, size of the ordered moment, or the relative scale of the Kondo and magnetic ordering temperatures. This raises the question of the role of each energy scale in driving the ground state properties. In focusing on a single class of compounds, the rhombohedral R${\mathrm{Rh}}_{3}{\mathrm{Si}}_{7}$, we compare the anisotropy and magnetic ground states in members of this series with only RKKY interactions (R = Gd), or RKKY and CEF effects (R = Tb-Tm), with the behavior of the R = Yb compound, where all three energy scales (RKKY, CEF, Kondo) are at play. Moreover, we extend the comparison to two other isostructural Kondo systems ${\mathrm{YbIr}}_{3}{\mathrm{Si}}_{7}$ and ${\mathrm{YbIr}}_{3}{\mathrm{Ge}}_{7}$, where hard axis magnetic order is also observed. The non-Kondo compounds R${\mathrm{Rh}}_{3}{\mathrm{Si}}_{7}$ (R = Tb-Tm) lack the complexity of magnetic order along the hard CEF axis, pointing to the dominant role of the Kondo effect in driving this magnetic order. However, the CEF-RKKY competition is still responsible for complex magnetic ground states, and it appears that the electronic and magnetic degrees of freedom are entangled in all magnetic members of this series of compounds.

Optical evidence of local and itinerant states in Ce- and Yb-heavy-fermion compounds

The electronic properties of Cerium (Ce) and ytterbium (Yb) intermetallic compounds may display a more local or more itinerant character depending on the interplay of the exchange interactions among the 4f electrons and the Kondo coupling between 4f and conduction electrons. For the more itinerant case, the materials form heavy-fermions once the Kondo effect is developed at low temperatures. Hence, a temperature variation occurs in the electronic structure that can be traced by investigating the optical conductivity (σ(ω)) spectra. Remarkably, the temperature variation in the σ(ω) spectrum is still present in the more localized case, even though the Kondo effect is strongly suppressed. Here, we clarify the local and itinerant character in the electronic structure by investigating the temperature dependence in the σ(ω) spectra of various Ce and Yb compounds with a tetragonal ThCr2Si2-type crystal structure. We explain the temperature change in a unified manner. Above temperatures of about 100 K, the temperature dependence of the σ(ω) spectra is mainly due to the electron–phonon interaction, while the temperature dependence below is due to the Kondo effect.

Proteinous pancreatic lipase inhibitor is responsible for the antiobesity effect of young barley (Hordeum vulgare L.) leaf extract.

Young barley leaves (Hordeum vulgare L.) have various health effects and are employed as an ingredient in the production of health-promoting foods. Promoting antiobesity is one such health effect; however, the mechanism and bioactive compounds are unclear. In this research, young barley leaf extract (YB) was demonstrated to possess pancreatic lipase inhibitory activity. The addition of YB to a high-fat diet in mice increased fecal lipid content, indicating reduced absorption of lipids as the mechanism underlying antiobesity effect. The investigation of bioactive compounds in YB resulted in the identification of fructose-bisphosphate aldolase as a proteinous lipase inhibitor. Maximum inhibition of the protein was 45%, but inhibition was displayed at a concentration as low as 16 ng/mL, which is a characteristic inhibition compared with other reported proteinous lipase inhibitors.

Study of electrical conduction behaviour of Y6-xBa4(SiO4)6O2 oxyapatite doped with ytterbium ions

This paper reports the electrical conduction behaviour of Yttrium Barium Silicate Oxyapatite Y6-xBa4Ybx(SiO4)6O2, synthesized by solution combustion method where x varies from 0.01 mol% to 0.05 mol%.. The scanning electron microscopy was done for morphological analysis which shows the spheroidal shaped grains with average grain size of 35μm. The dielectric behaviour of the material was studied in the frequency range of 100Hz – 100KHz and temperature varying from 50°C - 400°C. The frequency dependent dielectric constant and dielectric loss has been plotted for different temperatures. Decrease in dielectric constant and dielectric loss with increase in frequency has been observed for YBaSiO:Yb compounds.

Two Phases Inside the Bose Condensation Dome of Yb_{2}Si_{2}O_{7}.

Recent experimental data on Bose-Einstein condensation of magnons in the spin-gap compound Yb_{2}Si_{2}O_{7} revealed an asymmetric Bose-Einstein condensation dome [G. Hester et al., Phys. Rev. Lett. 123, 027201 (2019)PRLTAO0031-900710.1103/PhysRevLett.123.027201]. We examine modifications to the Heisenberg model on a breathing honeycomb lattice, showing that this physics can be explained by competing anisotropic perturbations. We employ a gamut of analytical and numerical techniques to show that the anisotropy yields a field driven phase transition from a state with broken Ising symmetry to a phase that breaks no symmetries and crosses over to the polarized limit.