Abstract: In this work we report the results of structural and Mossbauer spectroscopy studies for Ba2Co2Fe12O22 samples prepared by coprecipitation following two different synthesis routes: route A (pH = 10, NaOH + Na2CO3 added dropwise), and route B (pH = 14, NaOH + Na2CO3 added one shot). The resulting powders were sintered for 4 h at different temperatures (700 °C to 1100 °C in steps of 100 °C). The sintered powders were characterized by x-ray diffraction (XRD) and room temperature Mossbauer spectroscopy. XRD and Mossbauer results of the sample prepared by route A and sintered at 700 °C revealed formation of spinel phases (CoFe2O4 and/or Fe3O4), BaCO3 and BaM-type phase. The Co2Y phase developed in the samples sintered at 800 °C and 900 °C with spinel species as impurities, and single (pure) Co2Y phase was obtained at higher temperatures. On contrast, XRD patterns and the Mossbauer spectra for the samples prepared by route B showed different results, where the sample sintered at 700 °C consisted of only spinel phases. The Co2Y phase developed at higher temperatures, coexisting with significant amounts of other phases.

Abstract: The JYFLTRAP double Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility offers excellent possibilities for high-precision mass measurements of radioactive ions. Around 400 atomic masses, including around 50 isomeric states, have been measured since JYFLTRAP became operational. JYFLTRAP has also been used as a high-resolution mass separator for decay spectroscopy experiments as well as an ion counter for fission yield studies. In this contribution, an overview of recent activities at the JYFLTRAP Penning trap is given, with a focus on nuclei discussed in the PLATAN2019 meeting.

Abstract: Ions of the isomer 229mTh are a topic of high interest for the construction of a “nuclear clock” and in the field of fundamental physics for testing symmetries of nature. They can be efficiently captured in Paul traps which are ideal for performing high precision quantum logic spectroscopy. Trapping and identification of long-lived 232Th+ ions from a laser ablation source was already demonstrated by the TACTICa collaboration on Trapping And Cooling of Thorium Ions with Calcium. The 229mTh is most easily accessible as α-decay daughter of the decay of 233U. We report on the development of a source for slow Th ions, including 229mTh for the TACTICa experiment. The 229mTh source is currently under construction and comprises a 233U monolayer, from which 229mTh ions recoil. These are decelerated in an electric field. Conservation of the full initial charge state distribution of the 229mTh recoil ions is one of the unique features of this source. We present ion-flight simulations for our adopted layout and give a final source design. This source will provide Th ions in their original charge state at energies suitable for capture in a linear Paul trap for spectroscopy investigations.

Abstract: In this work, we examined the effects of the of Nd by Ce substitution and of the nitrogenation in the structural and hyperfine magnetic properties of (Nd1-xCex)1.1Fe10CoTi with x = 0, 0.5 and 1 systems. The alloys were prepared, with high pure elements, by arc-melting and the pieces were then homogenized at 1100 °C for 48 h. The nitrogenation was carried out at 450 °C for 1 h with a pressure of 0.1 MPa. The X-ray diffraction analysis allowed to identify the ThMn12-type structure mainly with average weigh fraction of 68%. The obtained tetragonal ThMn12 structure type presented an increased lattice parameter after nitrogenation for all alloys. The rhombohedral structure Th2Zn17-type is also present in the alloys and their lattice parameters do not show important changes after the nitrogenation. The Mossbauer spectra were fitted with seven sextets and a small quadrupolar component, the sextets were associated to the Fe sites in the ThMn12-type and Th2Zn17-type phases. The mean field, 〈Bhf〉, improve for all alloys after nitrogenation process. The Nd1.1Fe10CoTi (x = 0) and (Nd0.5Ce0.5)1.1Fe10CoTi (x = 0.5) alloys that present weigh fractions of 75 and 73%, respectively, with the ThMn12−type tetragonal structure present a 〈Bhf〉 of 30.9 and 31.0 T, respectively, after nitrogenation. Then, they can be possible candidates for rare earth-lean permanent magnets.

Abstract: The Resonance Ionization Laser Ion Source (RILIS) system has been developed for the future on-line laser ion source for a new heavy ion accelerator, RAON, in Korea. A tunable laser system consisting of four Ti:Sapphire lasers pumped by a Nd:YAG laser has been set up for the application in the RILIS laser ion source development in the ISOL facility of the Rare Isotope Science Project (RISP)/IBS. As a milestone of extraction of rare isotopes produced through uranium fission, double magic nucleus of 132Sn is our first target. Three step resonance ionization schemes with four laser wavelengths, at 286 nm, 301 nm, 811 nm and 823 nm, have been investigated for Sn. In this paper, we present the recent results and the current status of the hot-cavity type laser ion source development in the off-line ion source test facility of RISP, including measurements of ionization efficiency and mass resolving power.

Abstract: Selective laser melting (SLM) as an additive manufacturing technology enables the quick production of complex shaped three-dimensional (3D) specimens directly from a metal powder. Various metal powders, including different steels, are used in this technology. The influence of the SLM process on the phase composition of the final 3D specimen has been examined by Mossbauer spectroscopy (MS) The surface quality has been examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The maraging steel 1.2709 (CL50WS), an iron-nickel steel alloy, which is often used in applications where high fracture toughness and strength are required has been investigated. The difference between the phase composition of the initial CL50WS powder and the final specimen identified via MS demonstrated transformation of a martensitic phase into an austenitic one. This transformation proceeds during the whole SLM process. SEM presented imperfections of the surface of the final specimen. The spherical and irregular pores were observed as well as the particles of initial powder bonded to face. Inhomogeneity of elements on the face has been observed by EDS.

Abstract: The effect of Bi doping of (La0.8Ca0.2)1-xBixFeO3 perovskites on structural and magnetic properties was investigated. X-ray diffraction, magnetometry and Mossbauer spectroscopy measurements were performed on the samples. The sol gel prepared samples were annealed at 800 °C, 900 °C and 1200 °C. The samples crystallize in an orthorhombic structure with a PNMA space group. The LCBFO800 samples have Mossbauer spectra with large sextets in accordance with the small grain size. The several spectral components observed in the sample series are in accordance with the ones found in literature. Hyperfine magnetic fields decrease slightly with Bi content and increase with annealing temperature. Isomer shifts and quadrupole splitting stay constant with composition and annealing temperature. Magnetometry measurements show that the antiferromagnetic behavior is dominate over the ferromagnetic one. Bi doping increases coercivity and decreases remanent magnetization, while annealing temperature increases coercivity and remanent magnetization.

Abstract: In the search of efficient laser resonance ionization schemes and optimal source parameters, offline laser ion source development is of importance for successful online radioactive beam delivery. An overview and update on recent TRIUMF’s resonance ionization laser ion sources (TRILIS) offline developments is presented. This includes titanium-sapphire (Ti:Sa) laser development and the investigation of the laser ionization efficiency dependence on source temperature and laser polarization.

Abstract: COALA is a new offline collinear laser spectroscopy setup for high-precision measurements and development work at TU Darmstadt, Germany. An introduction to the technique and the experimental setup is given and an overview of current projects with recent results is presented. The idea of a novel all-optical absolute charge radius determination is discussed.

Abstract: The CERN-MEDICIS facility aims to produce emerging medical radionuclides for the theranostics approach in nuclear medicine with mass separation of ion beams. To enhance the radioisotope yield and purity of collected samples, the resonance ionization laser ion source MELISSA was constructed, and provided the first laser ions at the facility in 2019. Several operational tests were accomplished to investigate its performance in preparation for the upcoming production of terbium radioisotopes, which are of particular interest for medical applications.

Abstract: X-ray diffraction (XRD), Fields Emission Scanning Electron Microscope (FE-SEM) with EDS and Mossbauer Spectroscopy (MS), were applied to investigate a newly fallen solid piece of debris named the Aba Panu meteorite, after a city in south western Nigeria (Lat: N 08° 14′ 25.7″ and Long: E 003° 33′ 47.0″). Matching X-ray diffraction results, together with the FE-SEM analysis confirms the presence of four kinds of iron-bearing minerals, namely olivine, pyroxene, kamacite (Fe-Ni alloys) and troilite (FeS). The Mossbauer spectra recorded at 295 K and 78 K consist of two strong paramagnetic doublets emanating from olivine of quadrupole splitting 2.9 mm/s and pyroxene of quadrupole splitting 2.1 mm/s. These are superimposed on two magnetic sub-spectra attributed to kamacite and troilite phases. From the Mossbauer sub-spectra absorption area, the ratio of the olivine absorption area to the pyroxene absorption area indicates that the meteorite can be classified as an L-ordinary chondrite. The mole fraction of the Fe end-member of olivine (fayalite) and the orthopyroxene (ferrosilite) calculated from the EDS data will be used to identify the petrographic type of the meteorite.

Abstract: Dilute Fe and Nb codoped SrTiO3-δ (STO) perovskites were prepared by a complex formation and thermal decomposition method. The structure, magnetization properties and chemical states of Fe and Nb codoped STO perovskites were characterized by XRD, VSM and Mossbauer spectrometry. Mossbauer spectra of 57Fe and Nb codoped STO perovskites consist of paramagnetic doublet and magnetic relaxation components. The 1% Fe + 5% Nb codoped STO sample showed the smallest lattice constant and the largest ferromagnetism among 0.5–4% Fe + 5% Nb codoped STO perovskites. The most distortion of cubic STO lattice and the largest magnetic relaxation in Mossbauer spectrum were observed for the 0.5% Fe and 5% Nb codoped STO perovskite. It is considered that diluted magnetism in this system is related with the deformation of cubic structure due to defects.

Abstract: This work presents the results of BiFeO3 and Bi0.9Eu0.1FeO3 multiferroic materials, synthesized via a simple solid-phase reaction method. Both of the synthesized materials were in the rhombohedral R3c structure as observed by X-ray diffraction (XRD). The presence of a doublet along with a sextet in Mossbauer spectra indicates an impurity phase (Bi2Fe4O9). The presence of Fe2+ ions are confirmed from Mossbauer spectroscopy study in the Bi0.9Eu0.1FeO3 sample. And the Bi0.9Eu0.1FeO3 exhibited a slight lattice distortion, observable from the results of XRD and Mossbauer spectra. We can conclude that growing of crystal homogeneity of Bi0.9Eu0.1FeO3 is better than BiFeO3.

Abstract: A laser ablation ion source has been built and tested at the COALA beamline. Time-of-flight measurements for various elements are sufficiently accurate to confirm the production of the intended ion species. Furthermore, the isotope shift between 40Ca+ and 44Ca+ has been determined on these bunched beams by collinear laser spectroscopy and compared to previous measurements. The frequency of the $4s{}{}^{2}\textit {S}_{1/2} \rightarrow 4p{}{}^{2}\textit {P}_{1/2}$ transition has been determined to $ u ^{\mathrm {D1}}_{0}=755 222 766.8(15)$ MHz for 40Ca+, as well as the corresponding isotope shift of 44Ca+ to 848.1(23) MHz. This is in a good agreement to more accurate measurements performed in a recent ion trap experiment and demonstrates the strength of the collinear-anticollinear approach to reduce systematic effects caused by the broad velocity distribution generated in the ablation process.

Abstract: Comparison of the Mossbauer spectra of the as-prepared native iron oxide nanoparticles (IONs) and the citrate-functionalized IONs demonstrates differences in the spectral shapes at room temperature and variations of the 57Fe hyperfine parameters at 80 K. The observed differences are claimed to result from capping the IONs with citrate, thus decreasing the particle-particle interaction while promoting interaction of the outer atomic layers of the IONs with the surface molecular coating.

Abstract: We explore alternative ways to Mossbauer spectroscopy such as nuclear forward scattering of synchrotron radiation, and synchrotron radiation perturbed angular correlation spectroscopy to reveal the elusive and long-sought hyperfine interactions in e-Fe. We indicate that synchrotron radiation perturbed angular correlation spectroscopy is the most viable method.

Abstract: The vibronic properties of two dimeric iron (II) high-spin complexes [5CpFeX]2 (5Cp = Pentaisopropyl-cyclopentadienyl, X = OH-(1), Br-(2)) have been studied using nuclear inelastic scattering (NIS). In order to assign the experimentally observed bands to the particular modes, theoretical calculations using density functional theory (DFT) have been performed based on the structural data obtained by X-ray crystallography. The calculated partial density of vibrational states (pDOS) reproduces the experimental data. Thus, we were able to assign almost each of the experimentally observed NIS bands to their corresponding molecular vibrational modes.

Abstract: The Mossbauer spectroscopy database compiled and maintained by the Mossbauer Effect Data Center (MEDC) is a unique, wide-scope Mossbauer-spectroscopy related information resource, which forms the basis of information services provided by the Mossbauer Effect Data Center to the worldwide scientific community. The Mossbauer Effect Reference and Data Journal (MERDJ) and the Mossbauer Web Access Database (MWAD), both published by MEDC, are widely known examples of the services that rely on the MEDC database. In recent years a further improvement of these services, especially that of MWAD, has been envisaged, and as a first step of the corresponding process the further development of the MEDC database was started. In the present work we introduce the main features of the MEDC database and the steps that have been already taken in the frame of its further development. Implications of the work regarding the associated services are also presented.

Abstract: The unprecedented flux of low energy antiprotons delivered by the Extra Low ENergy Antiprotons (ELENA) ring, being under commissioning at CERN, will open a new era for precision tests with antimatter including laser and microwave spectroscopy and tests ofits gravitational behaviour. Here we present an alternative to magnetic trapping to perform ultra-high precision laser spectroscopy of antihydrogen. The proposed scheme is to load the ultra cold anti-hydrogen atoms produced by the GBAR experiment in an optical trap tuned at the magicwavelength of the 1S–2S transition in order to measure this interval at a level comparable or even better than its matter counter part. This will provide a very accurate test of Lorentz/CPT violating effects which can be parametrised in the framework of the Standard Model Extension.

Abstract: The aim of this paper is to report on the present status of the GAs cell based Laser ionization and separation Setup (GALS project) that is under construction at the Flerov Laboratory of Nuclear Reactions (FLNR) of JINR, Dubna. This project is directed on production of neutron-rich isotopes in the region of the magic N = 126 neutron number using multi-nucleon transfer reactions. The laser laboratory extension based on new TiSa lasers was performed, options of using a straight sextupole (SPIG) or an S-shaped quadrupole ion guides in the setup were compared based on the computer simulations, and the work on the rest of the GALS subsystems is being continued.

Abstract: Collinear laser spectroscopy on stable palladium isotopes was performed at the IGISOL facility in Jyvaskyla in preparation for an experiment on its neutron-rich isotopes. Five transitions from different initial atomic states were tested, with the goal of finding the most spectroscopically efficient. The observed intensities afforded a comparison with atomic-level population predictions based on charge-exchange calculations. For some transitions hyperfine parameters of 105Pd were measured, which were found to be in good agreement with literature values. A King plot analysis was performed using the measured isotope shifts and known charge radii from literature to determine the atomic field and mass shift factors.

Abstract: In the nematic (N) phase, the molecular symmetry axis orients on average along one direction denoted as the director. The cholesteric (Ch) phase shows similar orientational order locally. However, the average molecular direction in the Ch phase rotates continuously around a direction perpendicular to the director. The cholesteric blue phase (ChBP) shows a double-twist orientational order that differs from the single-twist order of the Ch phase and also shows self-assembled three-dimensional lattice structure of defect lines of the orientational order in the mesoscopic spatial scale. The helical structure of the molecular orientation in ChBP brings the structural colour and photonic band gap into the wavelength range of visible light. Therefore, ChBP has been studied for applications to photonic elements and fast-response displays. We measured the molecular translational dynamics along the molecular long axis in the Ch phase, ChBP and the isotropic (Iso) liquid phase of the mixture system of the nematic liquid crystal 4′-heptyloxy-4-biphenylcarbonitrile and the chiral dopant (S)-4′-(2-methylbutyl)-4-biphenylcarbonitrile directly at the nanometric molecular scale by using quasi-elastic scattering spectroscopy using Mossbauer gamma ray. We successfully determined the timescale of the molecular translational motion in the Ch phase to be 40 ns, which is similar to the timescale of the N phase of 4′-n-octyl-4-cyanobiphenyl. In the ChBP and Iso phase, molecular motions occur on timescales similar to those of the Ch phase, suggesting that the molecular dynamics is insensitive to the presence of orientational order, the helical structure, and higher-order structure. Our results demonstrate that the molecular dynamics in both the Ch phase and ChBP can be measured by quasi-elastic gamma-ray-scattering spectroscopy, in addition to the time scales of molecular motions in the N and smectic phases. The present results greatly expand the possibility of using this spectroscopic technique for molecular-mobility studies of industrial liquid-crystalline materials, because Ch liquid crystals are widely used for display systems in addition to N liquid crystals.

Abstract: We report the results of optical pump-nuclear resonance probe experiments on the SCO complex [FeII(L-PtII(t-but-tpy))2](BF4)2 with L being 2,6-di(pyrazol-1-yl)-4-(trimethylsilylethynyl)pyridine) and t-but-tpy being 4,4′,4″-Tri-tert-Butyl-2,2′:6′,2″-terpyridine using a novel experimental set-up at the beamline P01, Petra III, DESY Hamburg. We investigate the changes in the spin state of the complex when it is excited by laser pulses of 766 nm wavelength and pulse width < 100 ps. Our simulations of the nuclear forward scattering data indicate a dominant low spin state along with some high spin fraction in the absence of laser pulses. We observe clear changes in the time-spectrum following the instant at which the laser pulse hits the sample. Furthermore, these alterations are recorded as the relative timing of the laser pulses with respect to the synchrotron pulses is varied.

Abstract: Assembled Fe(II) complex, [Fe(NCS)2(1,5-bpna)2·(0.6CH2Cl2)(C2H5OH)]n (powder sample) (1,5-bpna = 1,5-bis(4-pyridyl)naphthalene), was synthesized. The powder sample showed slight decrease in magnetic susceptibility with decreasing temperature. Small amount of low-spin state was observed in Mossbauer spectrum at 78 K for the powder sample, suggesting incomplete spin-crossover phenomenon. Single crystal of [Fe(NCS)2(1,5-bpna)2·(toluene)]n was obtained. Magnetic susceptibility for [Fe(NCS)2(1,5-bpna)2·(toluene)]n revealed high-spin state at all temperature region. X-ray structural analysis revealed the CH-π interaction between bridging ligand and guest toluene. Such interaction forced parallel structure around iron atom, which inhibits the decrease in Fe-N distance to become low-spin state.

Abstract: Fe2+ ions in Fe7(P2O7)4 were substituted by Zn2+and the magnetic properties and Mossbauer spectra of the new material were studied. The obtained sample of Zn5Fe2(P2O7)4 is isostructural with the parent Fe7(P2O7)4, which is orthorhombic with a C2221 space group. Magnetometry shows that the Neel temperature is TN = 15.4(1) K, which is in accordance with Mossbauer measurements performed at RT and 4.2 K.

Abstract: A gas-filled miniature Radio-Frequency Quadrupole (mini-RFQ) was recently implemented into the SHIPTRAP laser ablation ion source to thermalize the laser-ablated ions and thus improve production efficiency as well as sample preparation. This source provides reference ions of various elements for online experiments with the SHIPTRAP mass spectrometer. In addition, it can be used to provide long-lived rare and radioactive isotopes available only in small sample sizes for high-precision mass measurements or to study systematic uncertainties. The performance of the laser ablation ion source was simulated using the COMSOL Multiphysics modeling software package. These studies indicate that a revised mechanical geometry and an optimized RF field improve the performance significantly.

Abstract: While the nuclear deformation in the region around Z = 40 and N = 60 has been studied in great detail, the possible onset of nuclear deformation in the isotopic chain of krypton (Z = 36) is still a subject of controversy. Here, we present a high-precision mass measurement of the neutron-rich nuclide 96Kr, as measured by the Multiple-Reflection Time-of-Flight Mass Spectrometer (MR-TOF-MS) at TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN). A statistical method, based on a hyper-exponentially modified Gaussian, has been employed to model the data. As such, the uncertainty introduced by overlapping peaks from beam contaminants was reduced and the mass excess of 96Kr determined to be -53097(57)keV. The capability of the method has been confirmed with measurements of the stable isotopic pair 40Ar/40Ca, in which a relative accuracy Δm/m of 3.5 ⋅ 10− 8 and a mass resolving power of more than 400000 were achieved.

Abstract: Radiation-damaged allanite-(Ce) starts to recrystallize at an annealing temperature below 700 K. At the same temperature Fe2+ → Fe3+ oxidation, as well as dehydration occurs. Three radiation-damaged samples (S74 20414: 0.55 wt% ThO2, LB-1: 1.18 wt% ThO2, R1: 1.59 wt% ThO2) as well as one crystalline sample (RS221) were investigated using 57Fe Mossbauer spectroscopy after step-wise annealing. Additionally, the three damaged samples were investigated by in-situ mass spectrometry, analysing the escaping gases during thermal treatment showing the dehydration process. 57Fe Mossbauer spectroscopy revealed not only a general Fe2+ → Fe3+ oxidation, it also showed that this process is not fully completed after annealing at 1000 K in sample LB-1 which is the sample showing the fastest and strongest recrystallization. The crystalline sample also still incorporated Fe2+ as well as Fe3+ after annealing at 1000 K. In addition, a preferred occupation of iron at the position M3 was identified in the crystalline sample which did not occur in the pristine radiation-damaged samples (M1/M3 site distribution: RS221: 17/83, pristine samples R1: 49/51, LB-1: 60/40, S74 20414: 52/48). After annealing at 1000 K sample LB-1 showed a similar distribution as the crystalline sample with a M1/M3 distribution of 15/85. It is therefore proposed that the process of amorphization through α-decay damage changes the distribution of iron atoms on its possible crystallographic sites, and that this process is reversible through thermal annealing.

Abstract: In this work, we employed the Laser Floating Zone (LFZ) method to grow the ceramic fibers with composition of 50Fe2O3-50SiO2 and 90Fe2O3-10SiO2, with two different pulling rates: 25 and 200 mm/h. The physical properties of the ceramics were studied as the function of the iron oxide content and the pulling rate. XRD analysis depicted that the main crystalline phase formed in all samples is magnetite. Although, the appearance of small quantity of nano-crystalline fayalite was also confimed. From the magnetic measurements, a Verwey transition for all LFZ fibers in the temperature range varying from 100 to 115 K depending on the composition and the pulling rate, was observed. Room temperature 57-Fe Mossbauer measurements showed that the degree of non-stoichiometry of LFZ ceramics with 90% of the iron content is higher than one for LFZ samples containing 50% of iron oxide. A great agreement was obtained between the result of Mossbauer spectroscopy measurements and VSM studies. The revealed behaviours can be described in terms of the temperature dependent interactions occurring between the magnetic clusters formed in the fibres.