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International audience; Excited states in Ba131 and Ce133 were studied using in-beam γ-ray spectroscopy through the Sn122(C13,4n)Ba131 and Te125(C12,4n)Ce133 reactions, respectively. A strongly coupled band, associated with the νg7/2[404]7/2+ configuration, was identified in Ba131 and Ce133. It is the first time to observe the νg7/2[404]7/2+ bands in the N=75 isotones. The signature partners exhibit considerable energy splitting in comparison with those in the πg7/2[404]7/2+ bands in the odd-A Ta and Re isotopes. Extensive cranked shell model and quasiparticle-plus-triaxial-rotor model calculations reveal the origin of the signature splitting, which depends not only on the triaxiality, but also on the configuration mixing with nearby low-j orbitals.

The $\beta$-decay of neutron-rich $^{129}$In into $^{129}$Sn was studied using the GRIFFIN spectrometer at the ISAC facility at TRIUMF. The study observed the half-lives of the ground state and each of the $\beta$-decaying isomers. The level scheme of $^{129}$Sn has been expanded with thirty-one new $\gamma$-ray transitions and nine new excited levels, leading to a re-evaluation of the $\beta$-branching ratios and level spin assignments. The observation of the $\beta$-decay of the (29/2$^{+}$) 1911-keV isomeric state in $^{129}$In is reported for the first time, with a branching ratio of 2.0(5)$\%$.

International audience; The high-spin states in Ba130 have been investigated using the Sn122(C13,5n) reaction and the GALILEO array coupled to the EUCLIDES and Neutron Wall ancillary detectors. The level scheme has been extended to an excitation energy of ≈12 MeV and spin 28. Two sets of pseudospin partner bands have been identified built on πh11/2(g7/2,d5/2) and νh11/2(s1/2,d3/2) configurations. The assignments are supported by calculations using the projected shell model and the particle rotor model.

The $^{80}$Ge structure was investigated in a high-statistics $\beta$-decay experiment of $^{80}$Ga using the GRIFFIN spectrometer at TRIUMF-ISAC through $\gamma$, $\beta$-$e$, $e$-$\gamma$ and $\gamma$-$\gamma$ spectroscopy. No evidence was found for the recently reported 0$_2^{+}$ 639-keV level suggested as evidence for low-energy shape coexistence in $^{80}$Ge. Large-scale shell model calculations performed in $^{78,80,82}$Ge place the $0^{+}_{2}$ level in $^{80}$Ge at 2\,MeV. The new experimental evidence combined with shell model predictions indicate that low-energy shape coexistence is not present in $^{80}$Ge.

Several new bands have been identified in $^{130}$Ba, among which there is one with band-head spin 8+. Its properties are in agreement with the Fermi-aligned νh11/22, 7/2−[523]⊗9/2−[514] Nilsson configuration. This is the first observation of a two-quasiparticle t-band in the A=130 mass region. The t-band is fed by a dipole band involving two additional h11/2 protons. The odd-spin partners of the proton and neutron S-bands and the ground-state band at high spins are also newly identified. The observed bands are discussed using several theoretical models, total Routhians surfaces (TRS), tilted axis cranking (TAC), particle rotor model (PRM) and projected shell model (PSM), which strongly suggest the coexistence of prolate and oblate shapes polarized by rotation aligned two-proton and two-neutron configurations, as well as prolate collective rotations around axes with different orientations. With the new results, $^{130}$Ba presents one of the best and most complete sets of collective excitations that a γ-soft nucleus can manifest at medium and high spins, revealing a diversity of shapes and rotations for the nuclei in the A=130 mass region.

The band built on the Kπ = 8−, T1/2 = 9.4 ms isomer of 130Ba has been identified, filling the gap in the systematics of the dipole bands built on the 8− isomers in the N = 74 isotones from 128Xe to 138Gd. The use of the GALILEO array in conjunction with its ancillaries EUCLIDES and Neutron Wall, helped to firmly place the newly identified transitions on top of the long-lived isomer. The extracted gK and gR gyromagnetic factors are in agreement with the 7/2+[404] ⊗ 9/2−[514] two-neutron Nilsson configuration. Particle-rotor model calculations give an understanding of the limited degree of K mixing. The experimental information on the Kπ = 8− isomer of 130Ba is now the most complete among the K isomers of the N = 74 isotones.

International audience; The half-life of the 42+ state of the 2p-2h proton intruder band of Sn116 has been measured with the fast-timing technique. The lifetime of T1/2=29(10) ps leads to a transition probability BE2;42+→22+=40(13) Weisskopf units, which is in very good agreement with the large BE2;22+→03+ value measured previously and provides strong support for the 03+ state as the bandhead of the intruder configuration and for the shape coexistence in the semimagic Sn116 nucleus. IBM-2 calculations with mixing reproduce the experimental data very well, giving insight into the degree of mixing between the different states.

Porous thermal barrier coatings (TBC) reduce the thermal load of gas turbine components. State-of-the-art TBCs consist of partially yttria-stabilized zirconia (PSZ) and are deposited by means of thermal spray techniques or electron beam physical vapor deposition. In this paper, an alternative, innovative deposition technique (reactive gas flow sputtering - GFS) is investigated and the influence of process parameters on the microstructure and the suitability of GFS coatings as TBCs is discussed. PSZ coatings were deposited on polished FeCrAlY-alloy substrates, with varying substrate temperature and oxygen flow rate, and characterized by means of SEM, and XRD. The substrate temperature is the crucial parameter. Between 500 and 800 °C, four types of columnar microstructures are found based on XRD pattern and morphology. The growth direction of the columns changes from to , accompanied by a change in shape from triangular to four-sided. Varying the oxygen flow rate at a given substrate temperature alters the microstructure defined by the substrate temperature. While oxygen flow rates above a certain level do not have an effect, low oxygen flow rates lead to further densification and compressive stresses, rendering these conditions unsuitable for TBC manufacturing. In conclusion, promising microstructures are presented accompanied by guidelines for process parameters.

This work investigates the influence of substrate temperature and applied bias voltage on the resulting microstructure and crystallographic properties of gas flow sputtered (GFS) partially yttria stabilized zirconia coatings (PSZ).On a FeCrAlY-alloy substrate PSZ coatings were deposited at substrate temperatures of 500 °C, 650 °C and 800 °C with bias voltages up to − 100 V and were subsequently analyzed utilizing SEM, FIB and XRD. Without bias voltage, all coatings were columnar and composed of small stacked platelets, but they varied in their porosity and morphology. Higher substrate temperatures lead to higher adatom mobility decreasing the porosity and the deposition rate. For all microstructures adistinct growth direction of the columns is observed changing from 〈111〉 (500 °C and 650 °C) to 〈100〉 (800 °C). For the 〈111〉 morphology, three ridges at intervals of 120° are observed throughout the whole column. In addition to the tetragonal/cubic phase, monoclinic fractions are found at the two lower substrate temperatures. The application of a negative bias voltage enhances the surface mobility of the film-forming adatoms and can cause densification due to atom displacements, resputtering or channeling phenomena. Moderate bias voltages up to − 40 V result in more regular columns and a lower porosity. For high bias voltages (− 100 V), the densification effects seem to dominate leading to fully dense coatings with residual stresses up to − 2.5 GPa and no preferential grain orientation, rendering this bias value unsuitable for thermal barrier coatings.

This paper reports on the deposition of Ni(x)Al(y) coatings on Ti-6Al- 2Sn-4Zr-6Mo by hollow cathode GFS (gas flow sputtering). It is possible to deposit Ni(x)Al(y) coatings with a large variety of mechanical properties, compositions and microstructures. The latter can be influenced significantly by variations of the bias voltage. Hydroxides or oxides can develop within the porosities due to multi-stage chemical processes during or after sampling the coated specimen out of the vacuum chamber. With regard to the nickel content in the coating, a significant enrichment can be observed for bias voltages of 50 V and more. With regard to the mechanical properties, it occurred that plastic hardness and elasticity correlate for variations of the substrate bias and the process pressure. The reduction of porosities for bias voltages of 25 and 50 V goes along with higher levels of hardness and elasticity. Peak values for both factors are found at U(ind B) = 50V, while the elastic indentation modulus reaches a minimum there. At U(ind B) = 150V, variations of the oxygen content do not occur for different process pressures. However, for high bias voltages an increasing process pressure can lead to a significant temperature increase at the substrate, which influences the mobility of the atoms during deposition. This effect can have a measurable impact on the mechanical properties and might explain the variations regarding hardness and elasticity for different process pressures. At U(ind B) = 50 V, it appears that these effects compensate as no significant variations can be observed. High compressive stresses were detected in the coating deposited without substrate bias. Due to the high porosity of the coating, this effect is attributed to the creation of oxides/hydroxides in the hollow spaces and the related increase in density. The variation of residual stresses between compressive and tensile state for bias voltages between 25 and 150 V is discussed. The results of this study can be used as a basis to diminish the fatigue strength reduction of Ti-6Al-2Sn-4Zr-6Mo components coated with an erosion resistant multilayer system. In contrast to the standard deposition parameter (U(ind B) = 25 V, p(ind Ch) = 0.49 mbar), a substrate bias of 50 V, for example produces a coating with a microcrystalline structure, higher hardness and elasticity values and a lower stiffness. Coatings like these might have the potential to diminish the propagation of cracks into the substrate.