Applied Magnetic Resonance最新文献

{"title":"Electron-Spin Relaxation of S3− in Ultramarine Blue and Lapis Lazuli","authors":"Sandra S. Eaton, Debbie G. Mitchell, Gareth R. Eaton","doi":"10.1007/s00723-024-01716-1","DOIUrl":"https://doi.org/10.1007/s00723-024-01716-1","url":null,"abstract":"<p>The blue color that has made lazurite (lapis lazuli) a prized mineral is due to the same S₃⁻ radical that is in synthetic ultramarine blue (UMB), which has been proposed as a CW EPR standard. Continuous wave and pulsed EPR spectra and relaxation times of S₃⁻ are compared for three commercial sources of synthetic UMB, for samples of lapis lazuli from Afghanistan, Chile, Colorado USA, and Pakistan, and a solution in DMSO:dioxane. The spin concentrations in the UMB samples were high, in the range of 3 × 10²⁰ to 5 × 10²⁰ spins/g. The field-swept echo-detected spectra of UMB samples have lineshapes at 4.2 K that depend on the field at which phase adjustment is performed, indicating strong spin–spin interaction. The spectra of the minerals included large spectral contributions from Mn²⁺, in addition to S₃⁻ for which the concentrations were 6 × 10¹⁸ to 2.9 × 10¹⁹ spins/g. Features in the spin-echo-detected spectra attributed to forbidden Mn²⁺ transitions were confirmed by comparison with Mn²⁺ spectra in CaO powder. Large distributions in relaxation times caused derived results to depend strongly on the experimental acquisition windows for echo decay and inversion-recovery curves. Short-phase memory times are attributed to spin–spin interactions and to motion of the S₃⁻ in the lattices. Relatively weak temperature dependence of spin lattice relaxation rates below or around 25 K is attributed to substantial spin–spin interaction and cross relaxation. The strong spin–spin interaction is not present for 0.4 mM S₃⁻ in DMSO:dioxane. The shorter <i>T</i>₁ for S₃⁻ than for SO₂⁻ or SO₃⁻ is attributed to stronger spin–orbit coupling.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"316 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adiabatic Control of the Phase Memory Relaxation in the Anticrossing Region","authors":"Yuri E. Kandrashkin","doi":"10.1007/s00723-024-01714-3","DOIUrl":"https://doi.org/10.1007/s00723-024-01714-3","url":null,"abstract":"<p>In the vicinity of the anticrossing region of the spin sublevels, the effective magnetic moment of the electron spin is reduced, resulting in an increase in the lifetime of the spin coherence. Based on this phenomenon, the modified electron spin echo protocol is proposed to extend the coherence relaxation time. It includes the Hahn echo sequence with the additional detuning of the magnetic field applied during the intervals between two pulses and between the refocusing pulse and the echo. The simplest system with anticrossing sublevels is an ion whose electron spin is strongly coupled to its own nucleus. To realize the proposed protocol, a narrow anticrossing region is required. The promising candidate to realize the proposed protocol is the crystal [Ho(W₅O₁₈)₂]⁹⁻, whose spin transitions have been studied in the recent paper (Kundu et al. Commun Phys 6:38 (2023)). Near the clock transition, the spin evolution of the electron–nuclear spin system is described by a fictitious spin 1/2, but with the magnetic properties dictated by the properties of the ion. The numerical study shows that the spin coherence is not destroyed by the magnetic field detuning, but it reduces the phase relaxation. In addition, the use of the unequal detuning pulses results in a phase shift of the spin echo, which can be used to discriminate between the target signal and the unwanted echo contributions.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"140 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards an EPR on a Chip Spectrometer for Monitoring Radiation Damage During X-ray Absorption Spectroscopy","authors":"Ekaterina Shabratova, Hadi Lotfi, Ayman Sakr, Mohamed Atef Hassan, Michal Kern, Matthias Neeb, René Grüneberger, Bastian Klemke, Gianluca Marcozzi, Klaus Kiefer, Aleksei Tsarapkin, Katja Höflich, Alina Dittwald, Andrea Denker, Jens Anders, Joseph E. McPeak, Klaus Lips","doi":"10.1007/s00723-024-01702-7","DOIUrl":"https://doi.org/10.1007/s00723-024-01702-7","url":null,"abstract":"<p>Electron paramagnetic resonance (EPR) spectroscopy is an essential tool to investigate the effects of ionizing radiation, which is routinely administered for reducing contaminations and waste in food products and cosmetics as well as for sterilization in industry and medicine. In materials research, EPR methods are not only employed as a spectroscopic method of structural investigations, but also have been employed for detection of changes in electronic structure due to radiation damage from high energy X-rays, for example, to monitor radical formation inside biomolecules caused by X-ray irradiation at carbon, nitrogen, and oxygen K-edges at synchrotron facilities. Here a compact EPR spectrometer, based on EPR-on-a-chip (EPRoC) sensor and a portable electromagnet, has been developed as a solution for monitoring radiation damage of samples during their investigation by X-ray absorption spectroscopy (XAS) at synchrotron facilities. A portable electromagnet with a soft iron core and forced air temperature stabilization was constructed as the source of the external magnetic field. The sweep range of magnetic field inside the most homogeneous region of the portable electromagnet is 12–290 mT. The compact spectrometer performance was evaluated by placing the EPRoC sensor inside either a commercial electromagnet or the portable electromagnet to record the EPR spectrum of tempol, irradiated alanine, and dilithium phthalocyanine (Li₂Pc). The potential performance of the portable spectrometer for the detection of radiation damage in organic compounds and transition metal-containing catalysts during XAS measurements in both fluorescence and transmission modes was calculated with promising implications for measurements after implementation in a synchrotron-based XAS spectrometer.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"4 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co2+ Doped SrZn2(PO4)2 Nanophosphor for White Light Emitting Applications","authors":"E. Naga Jyothi,&nbsp;Ch. Aswini,&nbsp;B. Preethi,&nbsp;N. Ch. Anjaneyulu,&nbsp;V. Khidhirbrahmendra,&nbsp;R. V. S. S. N. Ravikumar","doi":"10.1007/s00723-024-01711-6","DOIUrl":"10.1007/s00723-024-01711-6","url":null,"abstract":"<div><p>Co²⁺ doped strontium zinc phosphate (SZP) nanophosphor is prepared by solution combustion method. The synthesized nanophosphor is studied by structural and spectral characterizations XRD, SEM with EDS, FT-IR, Optical absorption, EPR and Photoluminescence. X-ray diffraction pattern confirmed a monoclinic crystal phase with a crystallite size of 57 nm with the help of Debye Scherrer’s formula. Morphological investigations indicate nanoflakes structure with average particle size determined in the nano range. EDS spectrum showed the existence of Strontium (Sr), Zinc (Zn), Phosphorus (P), Oxygen (O) and Cobalt (Co) in the synthesized sample. FTIR spectrum exhibited different vibrational bands corresponding to PO₄³⁻, P-O-P and other modes. Crystal field and inter-electron repulsion parameters are evaluated as Dq = 980, B = 920 and C = 3900 cm⁻¹. Comparing optical and EPR spectra confirms the inclusion of Co²⁺ ions in octahedral site geometry and covalent nature coupling with its host lattice. The evaluated photometric parameters such as CIE coordinates and Colour Correlated Temperature (CCT) values indicate that prepared Co²⁺ doped SZP nanophosphor is potentially good for white light emitting diodes and solid state lightening.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 10","pages":"1307 - 1322"},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Odd–Even Effect of Local Chain Dynamics in Polyelectrolyte Multilayers","authors":"Uwe Lappan, Ulrich Scheler","doi":"10.1007/s00723-024-01708-1","DOIUrl":"https://doi.org/10.1007/s00723-024-01708-1","url":null,"abstract":"<p>A spin label (SL) has been covalently attached to the weak polyanion poly(ethylene-<i>alt</i>-maleic acid) (P(E-<i>alt</i>-MA)) to study the dynamics of the polymer backbone in polyelectrolyte multilayers (PEMs) formed with the oppositely charged polycations branched poly(ethylenimine) (bPEI) and poly(allylamine hydrochloride) (PAH) by electron paramagnetic resonance (EPR) spectroscopy as a function of the number of layers <i>N</i>. The line shape of the spectra shows the superimposition of two spectral components: A slowly tumbling SL as the main component and an SL in the fast-motion regime as a minor component. The main component is assigned to chain segments of the polyanion interacting with the chain segments of the polycation. Simulations of the slow-motion spectra revealed that a pronounced odd–even effect occurred, i.e., the rotational dynamics of the P(E-<i>alt</i>-MA) chain segments is influenced by the polyelectrolyte in the terminating layer. The rotational mobility of the chain segments of the polyanion interacting with the oppositely charged bPEI is higher for odd number of layers <i>N</i>, i.e., when the polycation is on top, compared to even <i>N</i>. The dependence of the rotational dynamics on the number of layers <i>N</i> can also be observed in PEMs with PAH. It is assumed that the odd–even effect on rotational mobility is related to extrinsic sites within the PEMs. A probably large number of extrinsic sites in PEMs with an odd number of layers reduces the number of intrinsic binding sites, i.e., the density of temporary cross-links between the oppositely charged molecules decreases, which leads to increased rotational dynamics of the polyanion chain segments.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"42 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of Quantification of Quantitative Susceptibility Mapping for Estimating the Amount of Gadolinium Deposited in the Brain: a Preliminary Phantom Study","authors":"Yusuke Sato,&nbsp;Norio Hayashi,&nbsp;Tomokazu Takeuchi,&nbsp;Tetsuhiko Takahashi,&nbsp;Kouichi Ujita,&nbsp;Haruyuki Watanabe,&nbsp;Takayuki Suto,&nbsp;Yoshito Tsushima","doi":"10.1007/s00723-024-01709-0","DOIUrl":"10.1007/s00723-024-01709-0","url":null,"abstract":"<div><p>This study aimed to clarify the effects of different types of gadolinium (Gd)-based contrast agents (GBCAs) and different T1 values of Gd-containing materials on the R1 value and magnetic susceptibility of quantitative susceptibility mapping (QSM). GBCA dilution phantoms were prepared using five types to of GBCA evaluate their effects. The effect of different T1 values of substances with Gd was assessed. A 3.0 T-MR scanner with a 20-channel head/neck coil was used to acquire the R1 map and QSM for the phantom. Linear regression analysis was performed to evaluate the relationship between Gd concentration and R1 or magnetic susceptibility for each phantom. An analysis of covariance (ANCOVA) was employed to assess the consistency of the slopes. Linear regression analysis showed that Gd concentration had a high coefficient of determination for R1 values and magnetic susceptibility (<i>R</i>², 0.696–0.999; <i>p</i> &lt; 0.001). ANCOVA showed significant differences in the slopes of R1 values when different GBCA types were used (<i>p</i> &lt; 0.001), but no significant differences in the slopes for magnetic susceptibility (<i>p</i> = 0.719). Differences in surrounding T1 values significantly altered the intercepts and slopes of the measurements of R1 values and magnetic susceptibility (<i>p</i> &lt; 0.001). The change in slope was smaller for magnetic susceptibility than for R1 values. Thus, while R1 was minimally affected by the GBCA type, it varied with surrounding tissue T1 values. QSM, however, was unaffected by the GBCA type and less influenced by T1 values, suggesting QSM may offer more quantitative measurements of Gd compared to R1 maps.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 11","pages":"1403 - 1419"},"PeriodicalIF":1.1,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Analysis of Structural and Magnetic Properties in Co/Cu and Co/W Multilayers","authors":"M. Tokaç","doi":"10.1007/s00723-024-01704-5","DOIUrl":"10.1007/s00723-024-01704-5","url":null,"abstract":"<div><p>Gilbert damping in symmetric Cu/Co/Cu and asymmetric Cu/Co/W multilayers was studied as a function of Co thickness using FMR linewidth measurements. W-capped multilayers showed higher intrinsic damping across all thicknesses, due to strong SOC in W, which enhances spin-pumping, and MDL formation at the Co/W interface, increasing spin-flip scattering. The higher spin-mixing conductance in W-capped multilayers is linked to stronger SOC and enhanced orbital hybridization at the Co/W interface. X-ray diffraction revealed an fcc(111) phase in Co layers up to 4 nm thick, with thicker films showing a mix of fcc(111) and hcp(0001) textures. The Co thin films showed saturation magnetizations near literature values. No dead layer was found in Cu-capped multilayers, however, a 0.3 nm MDL formed in W-capped multilayers due to atomic intermixing at the Co/W interface. FM/NM interfaces are crucial in generating and dissipating pure spin currents, and they significantly impact the damping properties through the influence of seed and capping layers.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 11","pages":"1389 - 1402"},"PeriodicalIF":1.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benefitting from Magnetic Field-Induced Torquing in Terahertz EPR of a MnIII Coordination Complex","authors":"Thierry Dubroca, Andrew Ozarowski, Yukinari Sunatsuki, Joshua Telser, Stephen Hill, J. Krzystek","doi":"10.1007/s00723-024-01706-3","DOIUrl":"https://doi.org/10.1007/s00723-024-01706-3","url":null,"abstract":"<p>Manganese(III) (3d⁴, <i>S</i> = 2) coordination complexes have been widely studied by high-frequency and -field EPR (HFEPR) for their own inherent chemical interest and for providing information for the burgeoning area of molecular magnetism. In the present study, we demonstrate how a stable, easily handled complex of Mn^III, [MnLKNO₃], where L³⁻ is a hexadentate tripodal ligand, trianion of 1,1,1-tris[(3- methoxysalicylideneamino)methyl]ethane, can be used for another purpose entirely. This purpose is as a field and frequency standard for HFEPR that is superior to a “traditional” standard such as an organic radical (e.g., DPPH) with its single, <i>g</i> = 2.00 signal, or to atomic hydrogen, which is less readily available than DPPH and provides only two signals for calibration purposes (Stoll et al. in J Magn Reson 207:158–163, 2010). By contrast, polycrystalline [MnLKNO₃] (<b>1</b>) orients in the external magnetic field of an HFEPR spectrometer (three different spectrometers were employed in this study). The crystal structure of <b>1</b> allows determination of the exact, reproducible molecular orientation of <b>1</b> in the applied field. This phenomenon provides multiple, well-defined resonances over a broad field sweep range (0–36 T) at any of a wide range of frequencies (tested up to 1 THz so far) allowing accurate calibration of magnetic field in a multi-frequency HFEPR study.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"59 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interspin Distances in a Triarylmethyl Biradical from Two-Pulse Electron Spin Echo","authors":"Victoria N. Syryamina, Olga Yu. Rogozhnikova, Victor M. Tormyshev, Sergei A. Dzuba","doi":"10.1007/s00723-024-01707-2","DOIUrl":"https://doi.org/10.1007/s00723-024-01707-2","url":null,"abstract":"<p>Triarylmethyl (TAM) radicals and TAM-based biradicals are often used as spin labels in different applications. Pulsed dipolar spectroscopy (PDS) is developed for studying interspin distances in the important nanoscale range. Here, we describe synthesis of bis-triarylmethyl biradical and its study using a simple PDS approach based on two-pulse electron spin echo (2p ESE) spectroscopy. It is shown that despite the well-known problems of dead time, interference of electron–nuclear interactions, and fast signal decay, this approach can provide reliable information for the interspin distances. In this approach, strong dipole–dipole coupling can be easily accounted for in the data analysis.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"33 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Resonance and Magnetometry: Complimentary Tools for Probing Different Size Scales in Lithium-Ion Batteries","authors":"Joshua R. Biller, Adrienne Delluva, Kevin Finch","doi":"10.1007/s00723-024-01699-z","DOIUrl":"https://doi.org/10.1007/s00723-024-01699-z","url":null,"abstract":"<p>Lithium-ion batteries (LiB) function because of interconnected chemical and physical reactions across a wide range of size scales—from the overlap of atomic orbitals to flexing of the “lattice” upon lithiation/delithiation to the size/morphology of the particles that make up an electrode film. The cathode electrode in a LiB is based on very high concentrations of transition metals like Fe, Co, and Ni with unique unpaired electron spin environments. Further complexity results from changes to the number of unpaired spins available via redox chemistry, and three-dimensional interactions between spin centers through the lattice. These longer range interactions include ferromagnetic/ferrimagnetic/antiferromagnetic ordering, super-exchange, and the presence of magnetic polarons. Thus, while LiB are commonly viewed first as electrochemical in nature, their magnetic nature is just as important to consider, and their performance and state of health should be interpreted in terms of magnetic changes in the material. We have previously observed fully constructed, commercial 18650 NCA, LCO, and LPO batteries have characteristic magnetic fields up to several hundred micro-Tesla, and this measured field changes in response to different SOH or SOC conditions of the cell. That such a strong magnetic field can be measured is both amazing and very surprising. In this review, we will explore LiB magnetic characterization across all size scales by reflecting on advances in SQUID magnetometry, NMR, EPR, and <i>operando</i> magnetometry. We make a first attempt at answering the question of why there is such a strong magnetic signal to measure on commercial LiB. Understanding the effect of a rich unpaired spin environment across size scales will undoubtedly lead to a better understanding of LiB function and may give insight to improved manufacturing approaches and longer use lifetimes. On the 80th anniversary of Zavoisky’s discovery of EPR, we consider the cathode materials of LiB a “symphony of unpaired electrons” and see that advances in EPR, NMR, and magnetometry are needed now more than ever to understand our technologically complex world.</p>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"64 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}