Ba Isotopes Research Articles

Dissolved and Particulate Barium Distributions Along the US GEOTRACES North Atlantic and East Pacific Zonal Transects (GA03 and GP16): Global Implications for the Marine Barium Cycle

AbstractProcesses controlling dissolved barium (dBa) were investigated along the GEOTRACES GA03 North Atlantic and GP16 Eastern Tropical Pacific transects, which traversed similar physical and biogeochemical provinces. Dissolved Ba concentrations are lowest in surface waters (∼35–50 nmol kg−1) and increase to 70–80 and 140–150 nmol kg−1 in deep waters of the Atlantic and Pacific transects, respectively. Using water mass mixing models, we estimate conservative mixing that accounts for most of dBa variability in both transects. To examine nonconservative processes, particulate excess Ba (pBaxs) formation and dissolution rates were tracked by normalizing particulate excess 230Th activities. Th‐normalized pBaxs fluxes, with barite as the likely phase, have subsurface maxima in the top 1,000 m (∼100–200 μmol m−2 year−1 average) in both basins. Barite precipitation depletes dBa within oxygen minimum zones from concentrations predicted by water mass mixing, whereas inputs from continental margins, particle dissolution in the water column, and benthic diffusive flux raise dBa above predications. Average pBaxs burial efficiencies along GA03 and GP16 are ∼37% and 17%–100%, respectively, and do not seem to be predicated on barite saturation indices in the overlying water column. Using published values, we reevaluate the global freshwater dBa river input as 6.6 ± 3.9 Gmol year−1. Estuarine mixing processes may add another 3–13 Gmol year−1. Dissolved Ba inputs from broad shallow continental margins, previously unaccounted for in global marine summaries, are substantial (∼17 Gmol year−1), exceeding terrestrial freshwater inputs. Revising river and shelf dBa inputs may help bring the marine Ba isotope budget more into balance.

Barium stable isotopic composition of chondrites and its implication for the Earth

Barium is a refractory and fluid mobile element that is highly incompatible in basaltic systems. The elemental and isotopic compositions of Ba are used to trace fluid processes or sediment recycling during subduction. However, the Ba isotopic composition of primitive meteorites (chondrites), which represents the possible building blocks of terrestrial planets, is presently poorly known. Here, we report high precision Ba isotopic compositions of major types of chondrites using a double-spike method. Chondritic meteorites without clear terrestrial weathering show relatively homogeneous Ba isotopic distributions and have an average δ137/134Ba (the permil deviation of the 137Ba/134Ba ratio from the SRM3104a standard) value of 0.09 ± 0.09‰ (2SD, N = 14). Given the refractory and lithophile behavior of Ba and the limited variations of Ba isotope composition between various chondrite groups, this value can represent the Ba isotopic composition of the bulk Earth and the Bulk Silicate Earth (BSE). It is actually consistent with the present estimate of BSE (0.05 ± 0.06‰, Li et al., 2020; Nan et al., 2022) based on the measurements of mid-ocean ridge basalts and carbonatites. Small Ba isotope variations are observed between carbonaceous chondrite groups where CO and CV show slightly heavier (by 0.09‰) Ba isotopic compositions than CI and CM. Significant light stable Ba isotopes enrichment has previously been documented in calcium, aluminum-rich inclusions (CAIs) in the Allende CV chondrite, and the Ba isotopic differences between CO and CV might result from the various proportions of CAIs based on a mass balance calculation. However, the parent body of CI and CM might have experienced aqueous alteration and secondary carbonates are most likely responsible for their light Ba isotopic signatures.

Monthly resolved coral barium isotopes record increased riverine inputs during the South Asian summer monsoon

We present a monthly resolved stable Ba isotope record (δ138Bacoral) of a young fossil coral (Porites) from the eastern side of the Andaman Islands (NE Indian Ocean), which grew prior to the 19th century. This δ138Bacoral record complements 19-years of monthly resolved Ba/Cacoral, Sr/Cacoral, U/Cacoral, δ18Ocoral and δ13Ccoral data from the same colony that can serve as a baseline of environmental variability before the industrialised era. The δ138Bacoral record exhibits small but significant seasonal variability ranging from 0.16 to 0.27 ± 0.03‰ over two continuous annual cycles. The δ138Bacoral signature is generally low during the South Asian summer monsoon (SAM, June-September) and post-SAM seasons (October-January), which are characterised by high Ba/Cacoral and more depleted δ18OSW values. We suggest that Ba desorption from suspended fluvial sediments followed by lateral advection are the main causes of the low δ138Bacoral and elevated Ba/Cacoral values during the SAM and post-SAM. However, this promising Ba proxy behaviour is interrupted by pronounced spikes of low δ138Bacoral and high Ba/Cacoral signatures observed during the pre-SAM season (February-May) throughout the 19-year record. Possible explanations for these spikes observed during dry seasons are (1) Ba enrichment associated with decreased mixed layer depth or (2) Ba release from sediments trapped by local fringing mangroves. Surface seawater from the coral site sampled over an annual cycle exhibits a wide range of dissolved δ138BaSW and [Ba]SW values, with significantly lowered δ138BaSW of 0.29 ± 0.04‰ and high [Ba]SW of 66.03 nmol/kg during the SAM, which is broadly consistent with the coral skeletal signals. Our results establish a clear link between monsoon-driven freshening events and Ba isotope variability of surface waters and assess the utility of coral skeletal Ba isotopes to trace riverine inputs into tropical coastal oceans.

Cluster decay half-lives of Ba112–122 isotopes from the ground state and intrinsic excited state using the relativistic mean-field formalism within the preformed-cluster-decay model

Background: The cluster radioactivity from the neutron-deficient trans-tin region of the nuclear landscape has given immediate attention in the nuclear structure studies. Recent prediction of the emitting clusters from the ground and intrinsic excited states of proton-rich Ba isotopes opens the direction to explore the corresponding decay characteristics. A theoretical probe is necessary for understanding the cluster decays of Ba isotopes.Purpose: In the present study, cluster-decay half-lives are calculated and their decay characteristics are investigated for even-even $^{112--122}\mathrm{Ba}$ isotopes in both ground and intrinsic excited states along the proton drip line.Method: The preformed-cluster-decay model (PCM) is employed for estimating the decay half-lives. The preformation probability $({P}_{0})$ of the cluster decay from the parent nuclei is calculated by using the well-known phenomenological formula of Blendowske and Walliser [Phys. Rev. Lett. 61, 1930 (1988)], supplemented with the newly proposed $Q$-value-based preformation factor for the cluster with mass ${A}_{c}>28$. The penetration probability is calculated from the interaction potential using the Wentzel-Kramers-Brillouin (WKB) approximation. The nucleon-nucleon ($NN$) potential and individual binding energy (BE) of the cluster and daughter nuclei are estimated from the microscopic relativistic mean-field formalism (RMF) and compared with those from experiments and the finite-range-droplet model for the estimation of the $Q$ values of the cluster decays. The nonlinear RMF Lagrangian from which the effective relativistic R3Y $NN$ potential is derived using the $\mathrm{NL}{3}^{*}$ parameter set is employed for the calculation of the nuclear matter densities. The R3Y and well-known M3Y potential are employed to obtain the cluster-daughter interaction potential using the double-folding procedure along with their corresponding RMF densities. The total potential along with their respective cluster decay $Q$ values are used as input in the PCM to obtain the half-lives (${T}_{1/2}$) of $^{112--122}\mathrm{Ba}$ isotopes in their ground and intrinsic excited states.Results: The calculated half-lives (${T}_{1/2}$) for relativistic R3Y $NN$ potential and $Q$ values are found to deviate slightly compared to the ones from the M3Y due to the difference in their barrier characteristics. We notice that at elongated neck configuration a minimum neck-length parameter $\mathrm{\ensuremath{\Delta}}R=1.0\phantom{\rule{4.pt}{0ex}}\text{fm}$ is required for R3Y potential due to its repulsive nature, whereas the value is $0.5\phantom{\rule{4.pt}{0ex}}\text{fm}$ is suitable for the M3Y case. However, the estimated decay half-lives for both the potentials are in reasonably good agreement with the experimental lower limit of $^{114}\mathrm{Ba}$. In contrast with the ground-state decays, the inclusion of intrinsic excitation reduces the corresponding half-life values considerably but does not rule out the role of magicity.Conclusions: The sensitivity of the decay half-lives to $Q$ values and neck-length parameter has also been demonstrated. The decay half-lives are predicted for various cluster decays from neutron-deficient Ba isotopes. Since none of the experimental half-lives for the examined clusters is precisely known yet, further studies with available observed half-lives will be needed to substantiate our findings.

Systematic Analysis for Neck-Length and Q-Values on Cluster Decay from Ba Isotopes

The present study provides a detailed investigation of the neck-configuration and Q-values on the cluster decay of proton-rich even-even 124-128Ba isotopes using the relativistic mean-field (RMF) formalism with the NL3* parameter set. The densities of the interacting nuclei from the RMF approach are folded with the R3Y and M3Y interactions to obtain the nuclear potential via the double-folding technique. The preformed cluster model (PCM) based on the quantum mechanical fragmentation theory is employed for the calculation of the decay half-lives. The preformation probability P0 and the penetration probabilities are estimated by the phenomenological scaling factor of Blendowske & Walliser and the WKB approximation respectively. The present investigation reveals that the M3Y and R3Y are associated with different barrier characteristics which are significantly modified with a little variation in the neck-length parameter ΔR. From the Q-value analysis, we have demonstrated that α-decay may not be a favourable decay mode for proton-rich barium isotopes with A > 122.

Experimental Investigation of Barium Sources and Fluid–Rock Interaction in Unconventional Marcellus Shale Wells Using Ba Isotopes

Experimental Investigation of Barium Sources and Fluid–Rock Interaction in Unconventional Marcellus Shale Wells Using Ba Isotopes

Barium isotope fractionation during dehydration melting of the subducting oceanic crust: Geochemical evidence from OIB-like continental basalts

Continental basalts commonly show ocean island basalts (OIB)-like geochemical compositions, and their origin is geochemically linked to metasomatism of the big mantle wedge by the deeply subducting oceanic slab at postarc depths of >200 km. This linkage is tested by a combined study of Ba isotopes with major-trace elements and Sr–Nd isotopes in Cenozoic continental basalts from eastern China. These basalts show OIB-like trace element distribution patterns and depleted to weakly enriched Sr–Nd isotope compositions, suggesting incorporation of the dehydrated slab component into their mantle sources. Their δ138Ba values vary from −0.05‰ to +0.06‰, which are lower than the depleted mid-ocean ridge basalts (MORB) mantle but similar to island arc basalts, OIB and OIB-like continental flood basalts. The variation of δ138Ba values cannot be ascribed to fractional crystallization and crustal contamination of mantle-derived magmas, but it results from mixing of the depleted mantle with the recycled crustal material of low δ138Ba values. In other words, the geochemical deviations from the depleted MORB mantle are attributable to the source mixing at mantle depths rather than the crustal contamination at crustal depths. Although the δ138Ba values of the dehydrated oceanic crust would be lower than the initially subducting crust based on the lower coordination number of Ba in liquid phases relative to solid phases in the crust, the low δ138Ba recycled crustal material including igneous oceanic crust (IOC) and seafloor sediment is still required to produce the low δ138Ba values for the studied basalts. The similarity in δ138Ba to island arc basalts not only indicates the similarly low δ138Ba values for the recycled crustal components in these basalts, but also suggests the limited Ba isotope fractionation during dehydration melting of the subducting oceanic crust at postarc depths.

The influence of black shale weathering on riverine barium isotopes

Barium and its isotopes are receiving growing interest in their capacity to record the variation of the oceanic biological pump through geological timescales. Nonetheless, only little is known about the continental sources and processes that can drive the Ba flux and isotope composition to the ocean. Whereas the role of processes such as secondary phase formation, sorption and biological uptake on Ba isotopes has been recently investigated, the potential of various rock sources in producing a range of Ba isotope compositions remains poorly known. In particular, black shales often exhibit enrichment in Ba that might potentially be associated with various Ba isotope signatures.In this study, we report the isotope composition of Ba in rivers with different relative contribution of black shale rocks in their catchments, located in the Mackenzie Basin (Northwest Canada). Both the dissolved and solid loads of the Mackenzie tributaries are enriched in heavy Ba isotopes with respect to the continental crust, which is consistent with an additional source to the weathering of igneous and siliciclastic rocks. Although the dissolved Ba abundance is partially driven by weathering processes, the river dissolved Ba isotope composition rather reflects a binary mixing between 1) a “classical” siliciclastic source (with a Ba isotope composition close to that of the upper continental crust δ138Ba ∼ 0.15 ± 0.05‰) and 2) an isotopically heavier source especially present in the Mackenzie Mountains (with a δ138Ba ∼ 0.40‰). The positive relationships between dissolved δ138Ba and radiogenic osmium isotope ratios, as well as with sulphuric acid production, indicate that the heavy Ba source is tightly linked to the weathering of black shale. Although the exact reason for such heavy Ba isotope signatures remains elusive, this study emphasises the potential of black shale weathering in shifting the Ba isotope composition of the dissolved flux to the ocean towards heavier values.

Crustal Contaminations Responsible for the Petrogenesis of Basalts from the Emeishan Large Igneous Province, NW China: New Evidence from Ba Isotopes

Crustal Contaminations Responsible for the Petrogenesis of Basalts from the Emeishan Large Igneous Province, NW China: New Evidence from Ba Isotopes

Multi-colony calibration of barium isotopes between shallow-water coral skeletons and in-situ seawater: Implications for paleo proxies

Barium incorporated in coral skeletons has been widely used as paleo proxies to study terrestrial inputs, upwelling and anthropogenic activities in marine environments. However, these applications often face the challenges of poor replication in the coral skeletal Ba/Ca records from multiple coral colonies and complex Ba sources in coastal environments. Recent studies of Ba isotopes in seawater and deep-sea corals have demonstrated the potential to trace Ba sources and water mixing in the ocean, but there is still a lack of calibrations for Ba isotopes in shallow-water corals. In this study, we present the first multi-colony Ba isotope calibration from three shallow-water Porites lutea corals with the contemporaneous in-situ seawater data from the Singapore Strait. We also report the Ba isotope data in the regional water masses around the study area (e.g. South China Sea, Malacca Strait and Johor River estuary). Singapore water Ba concentrations and isotope compositions show a strong influence of terrestrial inputs, following seasonal salinity and monsoon-driven water-mass mixing between the Malacca Strait and the South China Sea. The coral skeletal δ138/134Ba results are generally consistent between the three coral colonies and time-series data closely follow the seasonal δ138/134Ba variations in seawater. Despite the partition coefficient of Ba having a large uncertainty (DBa=0.91±0.29), the Ba isotope fractionation between the coral skeletons and seawater is relatively constant (Δ138/134Bacoral-sw=−0.28±0.06‰) and shows no significant difference between these corals. The mechanism controlling Ba incorporation and isotope fractionation in coral skeletons remains unclear, but the evidence clearly indicates that the coral skeletal Ba is originated from dissolved Ba in seawater. The constant offset of Ba isotopes between coral skeletons and seawater allows for reliable records of seawater δ138/134Ba values. Ba isotopes in coral skeletons could be used to reconstruct surface water salinity variability in the Singapore Strait, reflecting monsoon driven changes in regional water mass mixing.

Re-visiting barium isotope compositions of mid-ocean ridge basalts and the implications

Barium (Ba) isotopes can be used as potential tracers for crustal material recycling in the mantle. Determination of the Ba isotope composition of the depleted mantle is essential for such applications. However, Ba isotope data for mantle-derived basalts are still rare. In this study, we reported high-precision Ba isotope data of 30 oceanic basalts including 25 mid-ocean ridge basalts (MORBs) from geochemically and geologically diverse mid-ocean ridge segments and five back-arc basin basalts. The δ<sup>138/134</sup>Ba values of these samples varied from −0.06‰ to +0.11‰, with no systematic cross-region variation. Together with published data, we constrained the average δ<sup>138/134</sup>Ba of global MORBs to +0.05‰±0.09‰ (2 standard deviation, <i>n</i> = 51). Based on depleted MORBs that have (La/Sm)<sub>N</sub> < 0.8, low <sup>87</sup>Sr/<sup>86</sup>Sr (< 0.70263), and low Ba/Th < 71.3, we estimated the average δ<sup>138/134</sup>Ba of the depleted MORB mantle (DMM) as + 0.05‰ ± 0.05‰ (2SD, <i>n</i> = 16) that is significantly lower than the DMM (≈ 0.14‰) reported previously. If a new estimation of the DMM is applied, it is unreasonable to infer that the Ba isotope signatures of the “enriched-type” MORBs (E-MORBs) could be attributed to pervasive sediment recycling in the upper mantle. We, therefore, conclude that the Ba isotope compositions of the E-MORBs could be sourced from the incorporation of subducted altered oceanic crust and/or sediments depending on the Ba isotope composition and other geochemical information of the local mantle.

Ba isotope geochemistry of the mantle

钡（Ba）是大离子亲石碱土金属元素，也是流体活动元素。Ba在地幔熔融过程中高度不相容，因此在地壳中含量远高于地幔。Ba同位素在低温环境和流体作用下可发生显著的分馏，而在高温基性和中性岩浆过程中分馏有限。因此，近年来Ba同位素得到了越来越多的关注，成为示踪地壳物质俯冲再循环的新工具，特别有助于鉴别流体和沉积物对地幔的影响。准确获取上地幔Ba同位素组成是开展应用研究的前提，目前关于地幔Ba同位素组成的研究很少，还存在很大的争议。本文对Ba同位素分析方法、分馏机理和重要地质储库的组成进行了总结。本文重点讨论了幔源岩浆岩的Ba同位素变化，以及岩浆岩和变质岩中的Ba同位素分馏行为及潜在应用，并对当前存在的问题及未来的研究方向进行了展望。

Accurate determination of Ba isotope ratios in barite samples by LA-MC-ICP-MS

A new method for in situ determination of Ba isotope ratios in barite samples by LA-MC-ICP-MS.

Quadrupole-octupole coupling and the evolution of collectivity in neutron-deficient Xe, Ba, Ce, and Nd isotopes

The evolution of quadrupole and octupole collectivity in neutron-deficient Xe, Ba, Ce, and Nd nuclei near the ``octupole magic'' neutron number $N=56$ is investigated within the mapped $sdf$-IBM framework. Microscopic input is obtained via quadrupole and octupole constrained Hartree-Fock-Bogoliubov calculations, based on the parametrization D1M of the Gogny energy density functional. Octupole-deformed mean-field ground states are predicted for Ba and Ce isotopes near $N=56$. Excitation energies of positive- and negative-parity states as well as electric transition rates are computed with wave functions resulting from the diagonalization of the mapped IBM Hamiltonian. The parameters of the Hamiltonian are determined via the mapping of the mean-field potential energy surfaces onto the expectation value of the Hamiltonian in the condensate state of the $s$, $d$, and $f$ bosons. Enhanced octupolarity is predicted for Xe, Ba, and Ce isotopes near $N=56$. The shape/phase transition from octupole-deformed to strongly quadrupole-deformed near $N=60$ is analyzed in detail.

Quadrupole-octupole collectivity in the Xe, Ba, Ce and Nd isotopic chains described with mean field and beyond approaches

The impact of quadrupole and octupole collectivity in the dynamic of low-lying collective states is discussed for a set of Xe, Ba, Ce and Nd isotopes with neutron numbers 54 ⩽ N ⩽ 96. Mean field based methods including pairing are used in our microscopic description along with the Gogny D1M force. Starting with a set of Hartree–Fock–Bogoliubov constrained states we consider dynamic fluctuations of the collective variables by using the generator coordinate method. Related quantities like reduced electromagnetic transition probabilities B(E1) and B(E3) and negative-parity excitation energies and their behavior with neutron number are discussed and compared with the available experimental data. The coupling between the quadrupole and octupole degrees of freedom is found to be rather weak in all the considered nuclei and therefore the properties of the negative parity states can be reasonably well described in terms of the octupole degree of freedom alone. The results of the calculations point towards dynamically enhanced octupole correlations around the ‘octupole magic’ neutron numbers N = 56 and N = 88.

Positive parity low-spin states of even–odd 129−133Ba isotopes

The positive parity low-spin states of even-odd 129−133Ba isotopes were studied in this study using the Interacting Boson–Fermion Model (IBFM-1). The single fermion is predicted to be in one of three single-particle orbits: 2d5/2, 2d3/2, and 3s1/2. The Interacting Boson Model (IBM-1) was used to investigate the energy levels, electric quadrupole transition probabilities, and potential energy surface of even-even Barium isotopes (a core for even-odd nuclei).The measured positive parity low-state energy spectra and predicted energy levels, as well as the B(E2) transition probabilities, are reasonably consistent with the experimental data and previous research for Ba isotopes. The potential energy surface contour plot reveals that all interesting nuclei are deformed and have γ-unstable-like properties.

Stable Barium Isotope Dynamics During Estuarine Mixing

AbstractStable barium isotopes are a potential proxy for riverine inputs into the ocean that reflect monsoon variability and climate change. However, dissolved Ba isotope (δ138BaDBa) geochemistry in river estuaries, a dynamic land to ocean transition zone, has rarely been systematically examined to date. Here, we show that significant Ba isotope fractionation occurs at near‐zero salinities in the Yangtze and Pearl River Estuary, whereas conservative mixing dominates δ138BaDBa distributions beyond low salinities, which are well predicted by an ion exchange model. Elevated δ138BaDBa in the river endmember results from preferential removal of light Ba isotopes by adsorption to fluvial particles. Subsequently, δ138BaDBa rapidly drops to minimum signatures at increased salinities indicating particle desorption of isotopically light Ba. Nevertheless, the apparently conservative δ138BaDBa‐salinity relationship beyond the low‐salinity minimum in both estuaries provides a modern calibration for using Ba isotopes as a proxy for paleosalinity and river water inputs into the ocean.

Behavior of barium isotopes during high-pressure metamorphism and fluid evolution

Barium (Ba) and its stable isotopes are powerful geochemical tracers for the recycling of subducted materials into the convective mantle. However, this requires a good understanding of the behavior of Ba isotopes during subduction-zone fluid processes. Here we present the first integrated study on Ba isotopes for two eclogite-vein systems (Ganghe and Hualiangting) that formed at high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic conditions from the Dabie orogen, central China. The Ganghe system displays constant δ138/134Ba (−0.01‰ to 0.03‰) in the UHP eclogites but relatively high δ138/134Ba (0.17‰) in the HP vein. In contrast, in the Hualiangting system, δ138/134Ba of the UHP eclogites vary from −0.14‰ to 0.05‰, while δ138/134Ba of the multiple HP veins and the retrograded amphibolites range from −0.17‰ to 0.34‰ and from −0.11‰ to 0.46‰, respectively.The combined results suggest that Ba isotopes can be considerably fractionated during subduction-zone fluid processes. HP-UHP metamorphic dehydration of the eclogites during the early stages of exhumation can produce an isotopically heavy initial vein-forming fluid due to the preferential leaching of epidote enriched with heavy Ba isotopes from the host eclogites. However, such processes have limited effects on the bulk eclogites because the Ba-rich phengite exists as a residual phase. During vein formation, light Ba isotopes are preferentially enriched in minerals relative to the fluids, resulting in the residual fluids with high δ138/134Ba. In addition, the fluids released from the gneisses have negative δ138/134Ba which is different from the eclogites, indicating that Ba isotopes can be used to trace the source of the metasomatic fluids. This study demonstrates that the UHP metamorphic rocks and HP veins can record Ba isotope fractionation during subduction-zone metamorphism and fluid-rock interaction, and recycling of the metamorphic rocks could modify Ba isotopic composition of the mantle wedge and arc volcanics.

Spectroscopy of states in Ba136 using the Ba138(p,t) reaction

Background: The $^{136}$Ba isotope is the daughter nucleus in $^{136}$Xe $\beta\beta$ decay. It also lies in a shape transitional region of the nuclear chart, making it a suitable candidate to test a variety of nuclear models. Purpose: To obtain spectroscopic information on states in $^{136}$Ba, which will allow a better understanding of its low-lying structure. These data may prove useful to constrain future $^{136}$Xe $\to$ $^{136}$Ba neutrinoless $\beta\beta$ decay matrix element calculations. Methods: A $^{138}\mathrm{Ba}(p,t)$ reaction was used to populate states in $^{136}$Ba up to approximately 4.6 MeV in excitation energy. The tritons were detected using a high-resolution Q3D magnetic spectrograph. A distorted wave Born approximation (DWBA) analysis was performed for the measured triton angular distributions. Results: One hundred and two excited states in $^{136}$Ba were observed, out of which fifty two are reported for the first time. Definite spin-parity assignments are made for twenty six newly observed states, while previously ambiguous assignments for twelve other states are resolved.

Ba145 and La145,146 structure from lifetime measurements

The occurrence of octupole shapes in even-mass neutron-rich Ba isotopes has been well established. However, the situation with the odd-mass Ba and odd or odd-odd La nuclei around them is not so clear. In order to shed light on these less-studied isotopes, a fast-timing experiment was performed using the GRIFFIN spectrometer at TRIUMF-ISAC. A wealth of excited-state lifetimes in the 100 ps to few ns range have been measured in $^{144,145,146}\mathrm{Ba}$ and $^{145,146}\mathrm{La}$ populated in the ${\ensuremath{\beta}}^{\ensuremath{-}}$ and ${\ensuremath{\beta}}^{\ensuremath{-}}\text{\ensuremath{-}}n$ decay of $^{145,146}\mathrm{Cs}$. The results do not allow one to draw firm conclusions about the possible octupole deformation of these nuclei but suggest different spin and parity assignments than previous works. This work highlights the need for more detailed study of the odd and odd-odd isotopes in this region to properly understand their structure.