{"id":"430c351b-10a1-4a09-a4b9-8fc5bd5a54d7","arxiv_id":"2506.07717","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":4,"one_line_summary":"Ba3TbRu2O9 shows cooperative antiferromagnetic ordering of Tb4+ (L=0, S=7/2) and Ru4+ (S=1) moments below 9.5 K, with terbium in an unusual tetravalent state.","lead":"This paper uses neutron diffraction and magnetic measurements to map the magnetic structure of the perovskite Ba3TbRu2O9, reporting that terbium is tetravalent with a spin-only ground state and that ruthenium orders magnetically with about two Bohr magnetons. A general reader might care because it claims a rare cooperative ordering of 4d and 4f moments in a correlated oxide family, which could inform the design of multiferroic and magnetodielectric materials.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The Tb4+ valence assignment is not independently established; the susceptibility argument used to support it yields a per-Ru paramagnetic moment (1.94 μB) that contradicts spin-only S=1. A direct Tb valence probe is needed before the s-orbital and cooperative-ordering claims can be accepted.","rationale":"The reader's verdict is CONDITIONAL, and my reading does not move it. The paper has real strengths: a clean TOF neutron data set, a magnetic-structure refinement (including an explicit check that setting the Ru moment to zero degrades the fit), a plausible k=0 Shubnikov group, and internal consistency between the refined Ru ordered moment (~2 μB) and the final S=1 assignment. The weak point is not the neutron Rietveld itself but the interpretive layer built on the Tb valence. Tb4+ with a half-filled 4f7 shell is the only way the paper can claim an 's-like' L=0 terbium state and a chemically uniform Ru4+ dimer; if Tb were Tb3+, the charge balance would force Ru4+/Ru5+ mixed valence and the refined ~2 μB Ru moment would no longer uniquely evidence S=1 Ru4+. The bulk susceptibility and XPS offered in §3.1 are not conclusive for this pivot: the paper itself flags the ~1 eV Ru oxidation-state ambiguity, and the per-Ru effective moment of 1.94 μB obtained after subtracting a Tb4+ contribution is not the 2.83 μB expected for S=1 spin-only paramagnetism, so it cannot be cited as independent support. The s-orbital and cooperative-ordering claims therefore remain conditional pending a direct valence measurement. A Tb L3-edge XANES experiment is the cleanest single arbiter: Tb4+ and Tb3+ are well separated in white-line position and lineshape, and the sample is a powder, so the measurement is straightforward. If XANES confirms Tb4+, the central claim survives this specific objection; if not, the structural interpretation would need substantial revision. This is exactly the kind of check that should be added before the paper is accepted in full, and it is consistent with the reader's conditional recommendation.","tokens_in":10821,"tokens_out":11990,"duration_ms":154726,"concrete_test":"Measure Tb L3-edge XANES (or Tb 3d XPS with multiplet fitting) on the same Ba3TbRu2O9 powder against Tb3+ (e.g., Tb2O3) and Tb4+ (e.g., TbO2) standards. Tb4+ shows a distinct L3 white-line shift and lineshape relative to Tb3+; if the spectrum matches Tb3+, the 4f7 s-orbital Tb claim fails and the magnetic refinement must be redone allowing mixed Ru4+/Ru5+ configurations. If it matches Tb4+, the valence basis is secured, although the 1.94 μB vs 2.83 μB paramagnetic-moment discrepancy for S=1 would still need an explanation.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central interpretive claim—Tb4+ with 4f7 (L=0, S=7/2) and single-valence Ru4+ with S=1—rests on the valence assignment in §3.1. That assignment is not robust. (1) The XPS discussion itself concedes that Ru 3p binding-energy differences between oxidation states are only ~1 eV and could arise from different crystallographic environments; no quantitative Tb valence calibration is provided, so the Tb 4d peak positions do not establish Tb4+ over Tb3+. (2) The susceptibility route is circular in effect: μeff=8.4 μB is taken to rule out Tb3+ (9.72 μB) and to imply Tb4+ (7.94 μB); the per-Ru value is then computed from μ_Ru² = (8.4² − 7.94²)/2, giving 1.94 μB. But a spin-only S=1 paramagnet has μ_Ru = g√(S(S+1)) = 2.83 μB at g=2. The 1.94 μB number is instead the scale of the ordered moment (gS = 2 μB) later refined by neutron diffraction, so using it as a Curie-Weiss confirmation of S=1 is inconsistent. (3) A Tb3+ ion with a crystal-field-reduced susceptibility plus mixed-valent Ru4+/Ru5+ could plausibly reproduce the same bulk μeff; this possibility is not modeled. Since charge balance, the 4f7 s-orbital state, the 'single Ru valence' phrase, and the assignment of the refined Ru moment to S=1 all hinge on that valence, the load-bearing assumption is the unproven Tb4+ assignment.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper reports magnetic susceptibility, XPS, and time-of-flight neutron powder diffraction measurements on the 6H-perovskite Ba3TbRu2O9. The authors conclude that Tb adopts a tetravalent 4f7 configuration with L=0 and S=7/2 (an 's-like' state), that Ru is tetravalent with a spin-only S=1 ground state, and that both Tb and Ru moments order cooperatively below TN ≈ 9.5 K, with Tb moments in the bc-plane and Ru moments along the b-axis, including a collinear antiferromagnetic arrangement within the Ru2O9 dimers. The neutron refinement yields ordered moments of about 6.18 μB for Tb and 1.96 μB for Ru.","tokens_in":11248,"tokens_out":6468,"duration_ms":77222,"significance":"If the central claims are correct, this compound is exceptional within the Ba3RRu2O9 family: it would exhibit a Tb4+ s-orbital-like state, a nearly full Ru4+ spin-only moment, and simultaneous 4d-4f magnetic ordering, contrasting with other members where reduced Ru moments and higher-temperature Ru order are observed. The neutron diffraction work provides a concrete magnetic structure and a model refinement that appears technically credible, and the paper clearly identifies a previously unresolved question about the Tb and Ru ground states. The main fragility lies not in the neutron refinement itself but in the assignment of Tb4+ valence, which underpins the 's-orbital' claim, and in the susceptibility decomposition used to support the Ru S=1 state.","major_comments":[{"comment":"The susceptibility-derived per-Ru effective moment of 1.94 μB is not consistent with the claimed spin-only S=1 paramagnetic moment of g√(S(S+1)) = 2.83 μB. The value 1.94 μB is instead close to the ordered-moment scale gS = 2 μB later refined by neutron diffraction. Using this number as a Curie-Weiss effective moment to support S=1 is internally inconsistent; if the Ru paramagnetic moment is genuinely ~1.94 μB, then strong orbital reduction or a different ground state is implied, which contradicts the 'spin-only' description. This issue must be addressed, either by identifying the discrepancy or by presenting the neutron ordered moment as the only evidence for S=1.","section":"3.1, Eq. (1)"},{"comment":"The assignment of Tb4+ is load-bearing for the entire 's-orbital state' claim, but the evidence provided is not sufficient. The XPS data are not calibrated against Tb3+ and Tb4+ standards, and the Tb 4d binding energies in the reported range do not uniquely discriminate between the two valence states. The susceptibility argument assumes Tb4+ (7.94 μB) to derive the per-Ru moment, so it cannot independently justify the valence. An alternative scenario—Tb3+ with a crystal-field-reduced effective moment combined with mixed-valent Ru4+/Ru5+—could reproduce the observed bulk μeff ≈ 8.4 μB and is not modeled or discussed. A direct probe such as Tb L3-edge XANES or bond-valence-sum analysis is needed to establish Tb4+ before the central claim can be accepted.","section":"3.1 and Fig. S4"},{"comment":"The manuscript contradicts itself on the Ru ground state: the abstract and conclusion state spin-only S=1, while the final paragraph of the Introduction states 'spin-only moment of Ru (S=2, L=0)'. The neutron-refined ordered moment of 1.96 μB is consistent with gS = 2 μB for S=1, not with S=2 (which would give gS = 4 μB). This is not merely a typo because it directly concerns the paper's central claim; the Introduction must be corrected and the distinction between the paramagnetic effective moment (2.83 μB for S=1) and the ordered moment (2 μB) made explicit throughout.","section":"Sec. 1 and Abstract"},{"comment":"The refined Tb moment of 6.18 μB is compared to 'S=7/2' in the text, but the spin-only ordered moment for S=7/2 is gS = 7 μB, not 7.94 μB (the latter is the free-ion effective moment). The observed value is about 12% below 7 μB, which is not 'slightly smaller' as stated. The proposed explanations (g-factor slightly below 2, or incomplete saturation) are plausible, but they weaken the 'unconventional spin-only' characterization without quantitative support. A discussion of how a reduced Tb moment might arise while still supporting an L=0 state, or a check of whether the reduced moment is inherent to the refinement, is required.","section":"3.2, refined Tb moment"}],"minor_comments":[{"comment":"In the sentence describing the best fit, 'a combination of Γ11(Ψ5) for Ru' appears to be a typo: Table S2 and the preceding text indicate that the Ru b-axis moment corresponds to Γ11(Ψ9), not Γ11(Ψ5). Please correct this mismatch.","section":"Sec. 3.2"},{"comment":"The sentence 'This is consistent with the theoretical value of 7.94 μB for S=7/2 is' is grammatically incomplete and should be rewritten; it would also help to clarify that 7.94 μB is the free-ion paramagnetic effective moment, distinct from the ordered moment scale.","section":"Sec. 3.1"},{"comment":"The abstract mentions 'strong spin-lattice coupling' in Ba3TbRu2O9, but the paper does not present direct evidence for spin-lattice coupling; either cite specific prior work that establishes this for this compound or qualify the statement.","section":"Abstract"},{"comment":"The symbol for the Bohr magneton appears inconsistently as 'μb' and 'μB'; please standardize to μB.","section":"Throughout"},{"comment":"The text states that the magnetic intensity below TN appears at Q = 1.44, 1.86, 2.19, 2.52, 3.30 and 3.53 Å⁻¹ for reflections (101), (103), (211), (105), (213) and (210), respectively; the last assignment appears to be (210) but the numbering of reflections in the accompanying text and figure could be made clearer to avoid confusion.","section":"Sec. 3.2"}],"recommendation":"major_revision","confidential_remarks":"The neutron diffraction study itself appears to be a solid piece of work that makes a useful contribution to the magnetic structures of this 6H-perovskite family. The main risk is that the authors have overinterpreted the data by asserting Tb4+ and an 's-orbital' state on the basis of a weak valence assignment and a susceptibility decomposition that is internally inconsistent. I would encourage the editors to request additional experimental evidence for the Tb valence (e.g., XANES or bond-valence-sum from precise structural data) or a substantially revised discussion that clearly separates the neutron-derived ordered moments from the paramagnetic susceptibility analysis. The S=1 versus S=2 inconsistency in the Introduction is minor in principle, but it signals that the central spin-state claim has not been carefully checked across the manuscript."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"This paper is worth taking seriously, but the headline claim is not as solid as the abstract suggests. The neutron diffraction work is the real product: they solve the k=0 magnetic structure and show both Tb (6.18 μB) and Ru (1.96 μB) moments order below 9.5 K, with Tb in the bc-plane and Ru along b. That is new—Ref. 14 only saw Tb ordering—and the refinement looks credible, with reasonable R-factors and a check that zeroing the Ru moment ruins the fit. The collinear AFM dimer arrangement compared to the canted Ho and FM-bridged Nd members is a useful addition.\n\nSoft spots: the paper says Ru S=1 in the abstract and S=2 in the introduction; that internal contradiction should never survive. The susceptibility decomposition is also confused: they take μeff=8.4 μB, subtract Tb4+ spin-only 7.94, and get 1.94 μB per Ru, but a paramagnetic S=1 Ru should give 2.83 μB. The 1.94 number is the ordered moment, not the Curie-Weiss moment, so they are mixing two different quantities. The valence assignment itself is load-bearing. Tb4+ is inferred from the bulk effective moment and XPS, and the XPS discussion honestly concedes the ~1 eV shifts are ambiguous. A Tb3+ ion with crystal-field-reduced moment plus mixed-valent Ru could produce the same bulk moment. So the 's-orbital state' and 'single Ru valence' claims are not established.\n\nNone of this kills the central experimental result: the ordered moments are independently refined from neutron data, and the cooperative ordering is real. But the interpretation needs direct valence evidence (Tb L-edge XAS or resonant scattering) and the susceptibility section must be redone. The paper deserves peer review—the magnetic structure is a solid contribution—but it will need heavy revision before the claims can be accepted.","headline":"Solid neutron magnetic structure of Ba3TbRu2O9 with cooperative Ru-Tb ordering, but the Tb4+/S=1 interpretation is under-supported and the paper contradicts itself on Ru's spin.","tokens_in":11801,"tokens_out":3143,"would_cite":true,"duration_ms":35733,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"Neutron diffraction shows Tb4+ with no orbital moment and Ru4+ with a full S=1 moment, ordering together at 9.5 K.","keywords":["Ba3TbRu2O9","6H-perovskite","4d-4f spin ordering","s-orbital state","Tb4+ valence","time-of-flight neutron diffraction","antiferromagnetic structure","spin-only moment"],"falsifier":"Measure the terbium valence directly with X-ray absorption near-edge structure at the Tb L$_3$ edge; if the edge position matches Tb$^{3+}$ standards rather than Tb$^{4+}$, the $L=0$ s-state claim and the $S=7/2$ assignment cannot be sustained, and the refined 6.18 $\\mu_{\\rm B}$ Tb moment would need reinterpretation.","tokens_in":10652,"feed_emoji":"🧲","tokens_out":8281,"duration_ms":85123,"temperature":0.7,"pith_summary":"This paper tries to establish that in the 6H-perovskite Ba3TbRu2O9 the rare-earth ion Tb is tetravalent ($\\mathrm{Tb}^{4+}$, $4f^7$), so its orbital moment vanishes ($L=0$) and its magnetism is carried entirely by spin ($S=7/2$) — an s-like state normally reserved for Gd$^{3+}$. It also claims that Ru$^{4+}$ in the Ru$_2$O$_9$ dimers adopts a full spin-only $S=1$ moment of about $2\\,\\mu_{\\rm B}$, in contrast to the reduced moments seen in other members of this family. The two sublattices order in a single antiferromagnetic transition near 9.5 K: Tb moments lie in the $bc$-plane and Ru moments along the $b$-axis, with collinear antiferromagnetic arrangement inside every Ru$_2$O$_9$ dimer. If correct, the compound becomes a clear instance of cooperative 4d–4f ordering where the f-electron system contributes no orbital angular momentum, and it sharpens the picture of how ruthenium's spin state changes across the Ba$_3$R Ru$_2$O$_9$ series.","feed_headline":"Terbium acts like an s-orbital ion in this magnetic oxide","feed_subtitle":"Neutron diffraction shows both Tb and Ru order together at 9.5 K with full spin moments.","key_machinery":"The load-bearing object is the magnetic irreducible-representation analysis of the $P6_3/mmc$ space group with propagation vector $k=(0,0,0)$, which selects the basis vectors that both Tb and Ru moments can occupy. The refined magnetic structure combines Ru $\\Gamma_{11}(\\Psi_5)$ with Tb $\\Gamma_7(\\Psi_2)$ and $\\Gamma_{11}(\\Psi_5)$, yielding magnetic space group $P6'_3/m'm'c$; this is what fixes the Tb moment to the $bc$-plane and the Ru moment to the $b$-axis. A second essential piece is the spin-only s-state picture: for a $4f^7$ configuration Hund's rules give $L=0$, $J=S=7/2$ for Tb$^{4+}$ and $S=1$ for Ru$^{4+}$, so the ordered moments can be compared directly to these free-ion values. The neutron refinement itself is the mechanism that rules out a Tb-only model, because setting the Ru moment to zero degrades the fit.","core_discovery":"By combining magnetization, XPS, and time-of-flight neutron diffraction with irreducible-representation analysis of the $P6_3/mmc$ space group, the paper determines the magnetic structure of Ba$_3$TbRu$_2$O$_9$. The refined propagation vector is $k=(0,0,0)$ and the magnetic space group is $P6'_3/m'm'c$. Tb occupies $2a$ sites and orders in the $bc$-plane with a total moment of $6.18 \\pm 0.04\\,\\mu_{\\rm B}$, close to the spin-only value of $7/2$; the moment components along $b$ and $c$ are $\\pm 1.69\\,\\mu_{\\rm B}$ and $\\pm 5.95\\,\\mu_{\\rm B}$. Ru, on $4f$ sites, orders with moments of $1.96\\,\\mu_{\\rm B}$ along the $b$-axis, essentially the full spin-only $S=1$ value. All Ru spins within each Ru$_2$O$_9$ dimer are collinear and antiferromagnetically arranged, unlike the canted or ferromagnetic dimer structures found for the Ho and Nd members. The authors attribute the simultaneous ordering of both sublattices below $T_{\\rm N} \\approx 9.5$ K to strong Ru(4d)–Tb(4f) superexchange through the nearly linear Ru–O–Tb paths (angle 179.18°), and they interpret the Tb moment as arising from a Tb$^{4+}$ $4f^7$ configuration with $L=0$, a state they call s-like.","pith_inferences":["Direct Tb valence testing via X-ray absorption at the Tb L$_3$ edge would resolve the main ambiguity, since the paper's own XPS analysis allows for the possibility that the 1 eV shift reflects crystallographic environment rather than oxidation state.","If the Tb$^{4+}$ assignment holds, this compound provides a rare platform where a 4f ion behaves as a pure spin ($L=0$), so any multiferroic or magnetoelectric response would be driven by the Ru(4d) sublattice rather than rare-earth single-ion physics.","Polarized single-crystal neutron scattering could test whether the small 15.9° canting of the Tb moments is intrinsic or a powder-averaging artifact."],"forward_implications":["Within the Ba$_3$R Ru$_2$O$_9$ family, Ba$_3$TbRu$_2$O$_9$ becomes the first non-cerium member shown to support tetravalent rare-earth ions while still hosting a cooperative 4d–4f ordering transition.","That the refined Ru moment is 1.96 $\\mu_{\\rm B}$ implies the Ru$_2$O$_9$ dimers preserve a local $S=1$ spin instead of forming a molecular singlet or a heavily reduced moment state.","Because both sublattices order at the same $T_{\\rm N}$, the Ru(4d)-Tb(4f) exchange through the nearly linear Ru-O-Tb path must be strong enough to lock the two spin systems together.","With Tb contributing no orbital moment, the magnetic anisotropy in the ordered state cannot come from single-ion Tb crystal-field anisotropy, so it must arise from the Ru sublattice or from exchange anisotropy."],"supporting_citations":[{"why":"reported the earlier observation of AFM ordering near 9.5 K in Ba3TbRu2O9 and proposed Tb-only ordering, the baseline this study re-examines","marker":"[14]"},{"why":"shows cooperative Ru(4d)-Ho(4f) ordering with a canted AFM dimer structure, the principal contrast for the collinear Ru structure claimed here","marker":"[5]"},{"why":"shows the Nd member with ferromagnetic dimers arranged antiferromagnetically, another contrast for the Ru dimer spin arrangement","marker":"[12]"},{"why":"documents an S=1/2 Ru ground state in Ba3YRu2O9 from metal-metal bonding, supporting the claim that Ru spin state depends on environment","marker":"[3]"},{"why":"documents an S=3/2 orbital-selective Mott state in Ba3LaRu2O9, another environmental variation used to frame the S=1 result","marker":"[10]"},{"why":"shows Ce4+ in Ba3CeRu2O9 is non-magnetic with no Ru ordering, supporting the tetravalent-rare-earth scenario for single-valence Ru4+","marker":"[15]"},{"why":"provides the Rietveld refinement method used to fit the nuclear and magnetic neutron diffraction patterns","marker":"[19]"},{"why":"provides the irreducible-representation analysis used to identify the allowed basis vectors and magnetic space group","marker":"[20]"},{"why":"gives the Tb 4d binding-energy values that support the Tb4+ assignment","marker":"[21]"},{"why":"documents the roughly 1 eV binding-energy offset between Ru oxidation states, the ambiguity the paper acknowledges in its XPS analysis","marker":"[23]"}],"fun_headline_variants":["Tb's s-like state yields full spin moments and order","Cooperative Ru(4d)-Tb(4f) ordering seen in Ba3TbRu2O9","S-like Tb4+ and Ru4+ order together at 9.5 K","Collaborative spin ordering from Tb and Ru in an oxide","Unconventional Tb state gives spin-only 7/2 moment"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The paper's central claim depends on terbium being tetravalent, which is inferred from an effective moment of 8.4 $\\mu_{\\rm B}$ and XPS lines whose Ru$^{4+}$/Ru$^{5+}$ separation is only about 1 eV; if Tb is actually trivalent, the s-orbital state is not real.","fun_headline_variants_meta":{"raw":{"variants":["Tb's s-like state yields full spin moments and order","Cooperative Ru(4d)-Tb(4f) ordering seen in Ba3TbRu2O9","S-like Tb4+ and Ru4+ order together at 9.5 K","Collaborative spin ordering from Tb and Ru in an oxide","Unconventional Tb state gives spin-only 7/2 moment"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000651,"raw_usage":{"total_tokens":3108,"prompt_tokens":1193,"completion_tokens":1915,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":809,"completion_tokens_details":{"reasoning_tokens":1809}},"tokens_in":809,"tokens_out":1915,"duration_ms":16476,"temperature":1.0,"reasoning_tokens":1809,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-07T05:27:00.757335+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the terbium valence directly with X-ray absorption near-edge structure at the Tb L$_3$ edge; if the edge position matches Tb$^{3+}$ standards rather than Tb$^{4+}$, the $L=0$ s-state claim and the $S=7/2$ assignment cannot be sustained, and the refined 6.18 $\\mu_{\\rm B}$ Tb moment would need reinterpretation.","supporting_citations":[{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"reported the earlier observation of AFM ordering near 9.5 K in Ba3TbRu2O9 and proposed Tb-only ordering, the baseline this study re-examines"},{"cited_title":"Elemental mapping obtained from EDS analysis: (b) oxygen (O K), (c) terbium (Tb L), (d) ruthenium (Ru L), and (e) barium (Ba L)","cited_arxiv_id":null,"evidence_quote":"shows cooperative Ru(4d)-Ho(4f) ordering with a canted AFM dimer structure, the principal contrast for the collinear Ru structure claimed here"},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"shows the Nd member with ferromagnetic dimers arranged antiferromagnetically, another contrast for the Ru dimer spin arrangement"},{"cited_title":"1c, confirming the purity of the sample","cited_arxiv_id":null,"evidence_quote":"documents an S=1/2 Ru ground state in Ba3YRu2O9 from metal-metal bonding, supporting the claim that Ru spin state depends on environment"},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"documents an S=3/2 orbital-selective Mott state in Ba3LaRu2O9, another environmental variation used to frame the S=1 result"},{"cited_title":"Miiller, M","cited_arxiv_id":null,"evidence_quote":"shows Ce4+ in Ba3CeRu2O9 is non-magnetic with no Ru ordering, supporting the tetravalent-rare-earth scenario for single-valence Ru4+"},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"provides the Rietveld refinement method used to fit the nuclear and magnetic neutron diffraction patterns"},{"cited_title":"Doi and Y","cited_arxiv_id":null,"evidence_quote":"provides the irreducible-representation analysis used to identify the allowed basis vectors and magnetic space group"},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"gives the Tb 4d binding-energy values that support the Tb4+ assignment"},{"cited_title":"Sannigrahi, A","cited_arxiv_id":null,"evidence_quote":"documents the roughly 1 eV binding-energy offset between Ru oxidation states, the ambiguity the paper acknowledges in its XPS analysis"}],"review_version":1}