Crystal Electric Field Excitations Research Articles

Diffusive excitonic bands from frustrated triangular sublattice in a singlet-ground-state system

Magnetic order in most materials occurs when magnetic ions with finite moments arrange in a particular pattern below the ordering temperature. Intriguingly, if the crystal electric field (CEF) effect results in a spin-singlet ground state, a magnetic order can still occur due to the exchange interactions between neighboring ions admixing the excited CEF levels. The magnetic excitations in such a state are spin excitons generally dispersionless in reciprocal space. Here we use neutron scattering to study stoichiometric Ni2Mo3O8, where Ni2+ ions form a bipartite honeycomb lattice comprised of two triangular lattices, with ions subject to the tetrahedral and octahedral crystalline environment, respectively. We find that in both types of ions, the CEF excitations have nonmagnetic singlet ground states, yet the material has magnetic order. Furthermore, CEF spin excitons from the tetrahedral sites form a dispersive diffusive pattern around the Brillouin zone boundary, likely due to spin entanglement and geometric frustrations.

Magnetic structure and crystal field states ofPr2Pd3Ge5:μSRand neutron scattering investigations

We present the results of muon spin relaxation ($\ensuremath{\mu}\mathrm{SR}$), neutron powder diffration (NPD), and inelastic neutron scattering (INS) investigations on polycrystalline ${\mathrm{Pr}}_{2}{\mathrm{Pd}}_{3}{\mathrm{Ge}}_{5}$. The polycrystalline ${\mathrm{Pr}}_{2}{\mathrm{Pd}}_{3}{\mathrm{Ge}}_{5}$ is known to exhibit two antiferromagnetic transitions near ${T}_{\mathrm{N}1}=8.3$ K and ${T}_{\mathrm{N}2}=7.5$ K which is confirmed by the heat capacity measurements on the present sample. In the magnetically ordered state the NPD data show clear evidence for magnetic Bragg peaks, which for $T<{T}_{\mathrm{N}2}$ could be indexed with a propagation vector k = (1, 0, 0), and with k = (1, 0, 0.07) for ${T}_{\mathrm{N}2}<T<{T}_{\mathrm{N}1}$. We have determined the magnetic structure and found a canted antiferromagnetic structure of ordered ${\mathrm{Pr}}^{3+}$ moments. At 7.6 K we find an amplitude modulated incommensurate antiferromagnetic arrangement of ordered moments with a maximum ordered moment of 1.64(3) ${\ensuremath{\mu}}_{\mathrm{B}}$/Pr lying in the $ab$ plane tilted at about ${26}^{\ensuremath{\circ}}$ from the $b$ axis. At 1.8 K the antiferromagnetic structure is found to be commensurate with an ordered moment of 2.80(6) ${\ensuremath{\mu}}_{\mathrm{B}}$/Pr lying in the $ab$ plane tilted at about ${28}^{\ensuremath{\circ}}$ from the $b$ axis. Our zero-field $\ensuremath{\mu}\mathrm{SR}$ spectra at 1.5 K and at shorter time scale (below 0.5 $\ensuremath{\mu}\mathrm{s}$) reveal two oscillatory frequencies further supporting a long-range-ordered magnetic ground state. We have calculated the muon sites using the density functional theory calculation and present the results of internal field calculations at the muon stopping sites, which are in good agreement with the experimental observations. In the paramagnetic state, the INS data show three well defined CEF excitations near 8.0, 12.3, and 18.1 meV arising from the crystal electric field (CEF) split $J=4$ ground state of ${\mathrm{Pr}}^{3+}$. The CEF level scheme is deduced by analyzing the INS data by a model based on the CEF model.

Revealing the effect of interstitial oxygen on the low-energy crystal electric field excitations of Pr3+ in 214 -nickelates

We report an inelastic neutron scattering study (INS) on the low-energy crystal electric field (CEF) excitations of ${\mathrm{Pr}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{4+\ensuremath{\delta}}$ single crystals at various temperatures. The observed low-$E$ CEF level of the O-doped sample $(x=0,\phantom{\rule{4pt}{0ex}}\ensuremath{\delta}\ensuremath{\approx}0.24)$ at $\ensuremath{\sim}5.5\phantom{\rule{4pt}{0ex}}\mathrm{meV}$ appears at significantly lower energy than that of the Sr-doped sample $(x=0.5,\phantom{\rule{4pt}{0ex}}\ensuremath{\delta}=0.0)$ at $\ensuremath{\sim}8.5\phantom{\rule{4pt}{0ex}}\mathrm{meV}$. Applying the point charge (PC) model calculation, this has been interpreted as an effect of the interstitial oxygen via lowering the local symmetry and modifying the CEF environment of the central rare earth ${\mathrm{Pr}}^{3+}$ $(^{3}H_{4})$ ions.

Mesoscale interplay between phonons and crystal electric field excitations in quantum spin liquid candidate CsYbSe2

In quantum spin liquid candidate CsYbSe2, phonon coupling to a crystal electric field mode results in a vibronic bound state, and complex, mesoscale interplay between phonon modes and CEF modes is observed.

Importance of dynamic lattice effects for crystal field excitations in the quantum spin ice candidate Pr2Zr2O7

Pr$_2$Zr$_2$O$_7$ is a pyrochlore quantum spin-ice candidate. Using Raman scattering spectroscopy we probe crystal electric field excitations of Pr$^{3+}$, and demonstrate the importance of their interactions with the lattice. We identify a vibronic interaction with a phonon that leads to a splitting of a doublet crystal field excitation at around 55~meV. We also probe a splitting of the non-Kramers ground state doublet of Pr$^{3+}$ by observing a double line of the excitations to the first excited singlet state $E^0_g \rightarrow A_{1g}$. We show that the splitting has a strong temperature dependence, with the doublet structure most prominent between 50~K and 100~K, and the weight of one of the components strongly decreases on cooling. We suggest a static or dynamic deviation of Pr$^{3+}$ from the position in the ideal crystal structure can be the origin of the effect, with the deviation strongly decreasing at low temperatures.

Magnetic frustration in a metallic fcc lattice

Magnetic frustration in metals is scarce and hard to pinpoint, but exciting due to the possibility of the emergence of fascinating novel phases. The cubic intermetallic compound HoInCu$_4$ with all holmium atoms on an fcc lattice, exhibits partial magnetic frustration, yielding a ground state where half of the Ho moments remain without long-range order, as evidenced by our neutron scattering experiments. The substitution of In with Cd results in HoCdCu$_4$ in a full breakdown of magnetic frustration. Consequently we found a fully ordered magnetic structure in our neutron diffraction experiments. These findings are in agreement with the local energy scales and crystal electric field excitations, which we determined from specific heat and inelastic neutron scattering data. The electronic density of states for the itinerant bands acts as tuning parameter for the ratio between nearest-neighbor and next-nearest-neighbor interactions and thus for magnetic frustration.

Neutron scattering measurement of crystalline-electric fields in magnesium rare-earth selenide spinels

The symmetry of local moments plays a defining role in the nature of exotic grounds states stabilized in frustrated magnetic materials. We present inelastic neutron scattering (INS) measurements of the crystal electric field (CEF) excitations in the family of compounds MgRE$_2$Se$_4$ (RE $\in$ $\{$Ho, Tm, Er and Yb$\}$). These compounds form in the spinel structure, with the rare earth ions comprising a highly frustrated pyrochlore sublattice. Within the symmetry constraints of this lattice, we fit both the energies and intensities of observed modes in the INS spectra to determine the most likely CEF Hamiltonian for each material and comment on the ground state wavefunctions in the local electron picture. In this way, we experimentally confirm MgTm$_2$Se$_4$ has a non-magnetic ground state, and MgYb$_2$Se$_4$ has effective $S=\frac{1}{2}$ spins with $g_\parallel = 5.188(79)$ and $g_\perp = 0.923(85)~\mu_B$. The spectrum of MgHo$_2$Se$_4$ indicates a ground state doublet containing Ising spins with $g_\parallel = 2.72(46)$, though low-lying CEF levels are also seen at thermally accessible energies $\delta_E = 0.591(36)$, 0.945(30) and 2.88(7)~meV, which can complicate interpretation. These results are used to comment on measured magnetization data of all compounds, and are compared to published results on the material MgEr$_2$Se$_4$.

Deviation from the dipole-ice model in the spinel spin-ice candidate MgEr2Se4

In spin ice research, small variations in structure or interactions drive a multitude of different behaviors, yet the collection of known materials relies heavily on the `227' pyrochlore structure. Here, we present thermodynamic, structural and inelastic neutron scattering data on a new spin-ice material, MgEr$_2$Se$_4$, which contributes to the relatively under-explored family of rare-earth spinel chalcogenides. X-ray and neutron diffraction confirm a normal spinel structure, and places Er$^{3+}$ moments on an ideal pyrochlore sublattice. Measurement of crystal electric field excitations with inelastic neutron scattering confirms that the moments have perfect Ising character, and further identifies the ground state Kramers doublet as having dipolar-octupolar form with a significant multipolar character. Heat capacity and magnetic neutron diffuse scattering have ice-like features, but are inconsistent with Monte Carlo simulations of the nearest-neighbor and next-nearest-neighbor dipolar spin-ice (DSI) models. A significant remnant entropy is observed as $T\rightarrow0$~K, but again falls short of the full Pauling expectation for DSI, unless significant disorder is added. We show that these observations are fully in-line with what is recently reported for CdEr$_2$Se$_4$, and point to the importance of quantum fluctuations in these materials.

Direct Evidence for the Existence of Heavy Quasiparticles in the Magnetically Ordered Phase of CeRhIn5

It is a long-standing important issue in heavy fermion physics whether $f$-electrons are itinerant or localized when the magnetic order occurs. Here we report the {\it in situ} scanning tunneling microscopy observation of the electronic structure in epitaxial thin films of CeRhIn$_5$, a prototypical heavy fermion compound with antiferromagnetic ground state. The conductance spectra above the N\'eel temperature $T_N$ clearly resolve the energy gap due to the hybridization between local 4$f$ electrons and conduction bands as well as the crystal electric field excitations. These structures persist even below $T_N$. Moreover, an additional dip in the conductance spectra develops due to the antiferromagnetic order. These results provide direct evidence for the presence of itinerant heavy $f$-electrons participating in the Fermi surface even in the magnetically ordered state of CeRhIn$_5$.

Crystal electric field contribution to the thermoelectric power of the CeCoAl4 antiferromagnetic

We report on the thermoelectric power S(T), electrical resistivity and thermal conductivity measurements on the antiferromagnetic CeCoAl4 compound and on the nonmagnetic reference compound, LaCoAl4. The Néel temperature of CeCoAl4 is T[Formula: see text] = 13.5 K and a metamagnetic-like transition occurs in the magnetic field of about 7.5 T. We show that the magnetic contribution to the thermoelectric power, S[Formula: see text](T), exhibits a large peak due to the crystal electric field (CEF) at about 240 K and a small anomaly around the ordering temperature. Surprisingly, the CEF related S[Formula: see text](T) peak is close to the upper CEF excitation energy [Formula: see text] = 202 K, in contrast to the usual case of the peak position being located at a fraction of the observed CEF energy level. The applicability of different theoretical and phenomenological models describing the temperature dependence of the Seebeck effect S[Formula: see text](T) has been tested and finally a calculation is proposed, which incorporates a full CEF levels scheme.

Analysis of the crystal electric field parameters of YbNi4P2

The crystal electric field (CEF) scheme of YbNi4P2 is determined, based on experimental data from inelastic neutron scattering, heat capacity, susceptibility and NMR measurements. Despite the tetragonal crystal structure, 9 parameters are needed to describe the crystal field in YbNi4P2 due to the orthorhombic site symmetry of the Yb ion. A large basal plane anisotropy is detected by the local probe NMR. Our analysis yields CEF excitation energies of 8.5, 12.5 and roughly 30 meV and a ground state wave function that is dominated by the state. Furthermore, we present an analysis of the CEF scheme based on density functional theory calculations, which confirms the large basal plane anisotropy.

Understanding the magnetism in noncentrosymmetric CeIrGe3 : Muon spin relaxation and neutron scattering studies

The magnetic properties of a pressure induced noncentrosymmetric heavy-fermion superconductor CeIrGe$_3$ have been investigated by muon spin relaxation ($\mu$SR), powder neutron diffraction (ND) and inelastic neutron scattering (INS) techniques at ambient pressure. For completeness we have also measured the ac magnetic susceptibility $\chi_{\rm ac}(T)$, dc magnetic susceptibility $\chi(T)$, dc isothermal magnetization $M(H)$ and heat capacity $C_{\rm p}(T,H)$ down to 2 K. CeIrGe$_{3}$ is known to exhibit pressure induced superconductivity ($T_{\rm c}\approx 1.5$ K) at a pressure of 20 GPa and antiferromagnetic ordering at 8.7 K, 4.7 K and 0.7 K at ambient pressure. Our $\chi_{\rm ac}(T)$ and $\chi(T)$ data show an additional anomaly near 6.2 K which is also captured in $C_{\rm p}(T)$ data. From $\chi_{\rm ac}(T)$, $\chi(T)$ and $C_{\rm p}(T)$ measurements we infer three antiferromagnetic transitions above 2 K at $T_{\rm N1}= 8.5$ K, $T_{\rm N2}= 6.0$ K and $T_{\rm N3}= 4.6$ K. Our $\mu$SR study also confirms the presence of three transitions through the observation of one frequency for $T_{\rm N2} < T\leq T_{\rm N1}$, two frequencies for $T_{\rm N3} < T\leq T_{\rm N2}$ and three frequencies for $T\leq T_{\rm N3}$ in the oscillatory asymmetry. The ND data reveal an incommensurate nature of the magnetic ordering at $T=7$ K with the propagation vector k = (0,0,0.688(3)), and a commensurate magnetic structure at $T=1.5$ K with the propagation vector locked to the value k = (0,0,2/3) and magnetic moments oriented along the $c$ axis. The commensurate structure couples a macroscopic ferromagnetic component, resulting in a strong dependence of the lock-in transition temperature on external magnetic field. The INS data show two well defined crystal electric field (CEF) excitations arising from the CEF-split Kramers doublet ground state of Ce$^{3+}$.

Effect of chemical pressure on the crystal electric field states of erbium pyrochlore magnets

We have carried out a systematic study of the crystal electric field excitations in the family of cubic pyrochlores Er$_2B_2$O$_7$, with $B=$~Ti, Ge, Pt, and Sn, using neutron spectroscopy. All members of this family are magnetic insulators based on 4$f^{11}$ Er$^{3+}$ and non-magnetic $B^{4+}$. At sufficiently low temperatures, long-range antiferromagnetic order is observed in each of these Er$_2B_2$O$_7$ pyrochlores. Our inelastic neutron scattering measurements probe the transitions from the ground state doublet to excited crystal electric field states belonging to the $J=15/2$ Hund's rules manifold. This allows us to quantitatively determine the energy eigenvalues and eigenfunctions of these $(2J+1)=16$ states across the Er$_2B_2$O$_7$ series. The different ionic sizes associated with different non-magnetic $B^{4+}$ cations correspond to positive or negative chemical pressure, depending on the relative contraction or expansion of the crystal lattice, which gives rise to slightly different local environments at the Er$^{3+}$ site. Our results show that the $g$-tensor components, which characterize the anisotropy of the ground state doublet eigenfunctions, are XY-like for all four members of the Er$_2B_2$O$_7$ series. However, the XY anisotropy is much stronger for Er$_2$Pt$_2$O$_7$ and Er$_2$Sn$_2$O$_7$ ($\frac{g_{\perp}}{g_z} > 25$), than for Er$_2$Ge$_2$O$_7$ and Er$_2$Ti$_2$O$_7$ ($\frac{g_{\perp}}{g_z} < 4$). The variation in the nature of the XY-anisotropy in these systems correlates strongly with their ground states, as Er$_2$Ge$_2$O$_7$ and Er$_2$Ti$_2$O$_7$ order into $\Gamma_5$ magnetic structures, while Er$_2$Pt$_2$O$_7$ and Er$_2$Sn$_2$O$_7$ order in the $\Gamma_7$ Palmer-Chalker structure.

Magnetic Structure and Excitations in CeCuxAl4-x System.

CeCuAl3 crystallizing in the tetragonal BaNiSn3-type structure and CeCuxAl4-x solid solutions were investigated by means of elastic and inelastic neutron scattering. Powder neutron diffraction brought information on both temperature evolution of crystallographic parameters and magnetic order at low temperatures. No structural change was observed in the investigated temperature range from 1.5 to 300 K. Weak magnetic peaks outside nuclear Bragg positions observed in solid solutions with 0.90 ≤ x ≤ 1.10 were described by the propagation vector k = (0.40 + δx, 0.60 + δy, 0), where δx ≈ 0.02 and δy ≈ 0.01. The magnetic structure of CeCu0.75Al3.25 consists of two components: an anti-ferromagnetic one described by the same k and a ferromagnetic one with k0 = (0, 0, 0) and magnetic moments lying within the tetragonal basal plane. The evolution of magnetic excitations as a function of Cu-Al concentration in CeCuxAl4-x was studied by inelastic neutron scattering. The measured spectra of CeCuAl3 and the solution with x = 0.95 point to a three-magnetic-peak energy scheme, while only two excitations are expected from the local symmetry conditions on Ce atoms. The standard two-peak spectrum of crystal electric field excitations was observed for Cu-Al substitutions further from the 1:1:3 stoichiometry (x = 0.75 and 1.10). The intermediate concentrations (x = 0.90 and 1.05) exhibit spectra on the border between the former cases with a less clear pronounced first inelastic magnetic peak. The observed behavior is discussed considering the evolution of structural parameters in the CeCuxAl4-x system and the coupling between the lattice vibrations and the crystal electric field excitations.

Muon spin relaxation and inelastic neutron scattering investigations of the all-in/all-out antiferromagnetNd2Hf2O7

${\mathrm{Nd}}_{2}{\mathrm{Hf}}_{2}{\mathrm{O}}_{7}$, belonging to the family of geometrically frustrated cubic rare-earth pyrochlore oxides, was recently identified to order antiferromagnetically below ${T}_{\mathrm{N}}\ensuremath{\approx}0.55$ K with an all-in/all-out arrangement of ${\mathrm{Nd}}^{3+}$ moments, however, with a much reduced ordered state moment. Herein, we investigate the spin dynamics and crystal-field states of ${\mathrm{Nd}}_{2}{\mathrm{Hf}}_{2}{\mathrm{O}}_{7}$ using muon spin relaxation $(\ensuremath{\mu}\mathrm{SR})$ and inelastic neutron scattering (INS) measurements. Our $\ensuremath{\mu}\mathrm{SR}$ study confirms the long-range magnetic ordering and shows evidence for coexisting persistent dynamic spin fluctuations deep inside the ordered state down to 42 mK. The INS data show the crystal electric field (CEF) excitations due to the transitions both within the ground-state multiplet and to the first excited state multiplet. The INS data are analyzed by a model based on CEF and crystal-field states are determined. Strong Ising-type anisotropy is inferred from the ground-state wave function. The CEF parameters indicate the CEF-split Kramers doublet ground state of ${\mathrm{Nd}}^{3+}$ to be consistent with the dipolar-octupolar character.

Crystal electric field excitations in the quasicrystal approximantTbCd6studied by inelastic neutron scattering

We have performed inelastic neutron scattering measurements on powder samples of the quasicrystal approximant, ${\mathrm{TbCd}}_{6}$, grown using isotopically enriched $^{112}\mathrm{Cd}$. Both quasielastic scattering and distinct inelastic excitations were observed below 3 meV. The intensity of the quasielastic scattering measured in the paramagnetic phase diverges as ${T}_{\mathrm{N}}\ensuremath{\sim}22$ K is approached from above. The inelastic excitations, and their evolution with temperature, are well characterized by the leading term, ${B}_{2}^{0}{O}_{2}^{0}$, of the crystal electric field (CEF) level scheme for local pentagonal symmetry for the rare-earth ions [S. Jazbec et al., Phys. Rev. B 93, 054208 (2016)] indicating that the Tb moment is directed primarily along the unique local pseudofivefold axis of the Tsai-type clusters. We also find good agreement between the inverse susceptibility determined from magnetization measurements using a magnetically diluted ${\mathrm{Tb}}_{0.05}{\mathrm{Y}}_{0.95}{\mathrm{Cd}}_{6}$ sample and that calculated using the CEF level scheme determined from the neutron measurements.

Raman active high energy excitations in URu2Si2

We have performed Raman scattering measurements on URu2Si2 single crystals on a large energy range up to ∼1300cm−1 and in all the Raman active symmetries as a function of temperature down to 15K. A large excitation, active only in the Eg symmetry, is reported. It has been assigned to a crystal electric field excitation on the Uranium site. We discuss how this constrains the crystal electric field scheme of the Uranium ions. Furthermore, three excitations in the A1g symmetry are observed. They have been associated to double Raman phonon processes consistently with ab initio calculations of the phonons dispersion.

Hyperfine and crystal field interactions in multiferroic HoCrO3

We report a comprehensive specific heat and inelastic neutron scattering study to explore the possible origin of multiferroicity in HoCrO3. We have performed specific heat measurements in the temperature range 100 mK–290 K and inelastic neutron scattering measurements were performed in the temperature range 1.5–200 K. From the specific heat data we determined hyperfine splitting at 22.5(2) μeV and crystal field transitions at 1.379(5) meV, 10.37(4) meV, 15.49(9) meV and 23.44(9) meV, indicating the existence of strong hyperfine and crystal field interactions in HoCrO3. Further, an effective hyperfine field is determined to be 600(3) T. The quasielastic scattering observed in the inelastic scattering data and a large linear term mJ mol−1 K−2 in the specific heat is attributed to the presence of short range exchange interactions, which is understood to be contributing to the observed ferroelectricity. Further the nuclear and magnetic entropies were computed to be, ∼17.2 Jmol−1 K−1 and ∼34 Jmol−1 K−1, respectively. The entropy values are in excellent agreement with the limiting theoretical values. An anomaly is observed in the peak position of the temperature dependent crystal field spectra around 60 K, at the same temperature an anomaly in the pyroelectric current is reported. From this we could elucidate a direct correlation between the crystal electric field excitations of Ho3+ and ferroelectricity in HoCrO3. Our present study, along with recent reports, confirm that HoCrO3, and RCrO3 (R = rare earth) in general, possess more than one driving force for the ferroelectricity and multiferroicity.

RESPECT: Neutron resonance spin-echo spectrometer for extreme studies

We propose the design of a REsonance SPin-echo spECtrometer for exTreme studies, RESPECT, that is ideally suited for the exploration of non-dispersive processes such as diffusion, crystallization, slow dynamics, tunneling processes, crystal electric field excitations, and spin fluctuations. It is a variant of the conventional neutron spin-echo technique (NSE) by (i) replacing the long precession coils by pairs of longitudinal neutron spin-echo coils combined with RF-spin flippers and (ii) by stabilizing the neutron polarization with small longitudinal guide fields that can in addition be used as field subtraction coils thus allowing to adjust the field integrals over a range of 8 orders of magnitude. Therefore, the dynamic range of RESPECT can in principle be varied over 8 orders of magnitude in time, if neutrons with the required energy are made available. Similarly as for existing NSE-spectrometers, spin echo times of up to approximately 1μs can be reached if the divergence and the correction elements are properly adjusted. Thanks to the optional use of neutron guides and the fact that the currents for the correction coils are much smaller than in standard NSE, intensity gains of at least one order of magnitude are expected, making the concept of RESPECT also competitive for operation at medium flux neutron sources. RESPECT can also be operated in a MIEZE configuration allowing the investigation of relaxation processes in depolarizing environments as they occur when magnetic fields are applied at the sample position, i.e. for the investigation of the dynamics of flux lines in superconductors, magnetic fluctuations in ferromagnetic materials, and samples containing hydrogen.

Crystal-field states of Kondo lattice heavy fermionsCeRuSn3andCeRhSn3

Inelastic neutron scattering experiments have been carried out to determine the crystal field states of the Kondo lattice heavy fermions CeRuSn3 and CeRhSn3. Both the compounds crystallize in LaRuSn3-type cubic structure (space group Pm-3n) in which the Ce atoms occupy two distinct crystallographic sites with cubic (m-3) and tetragonal (-4m.2) point symmetries. The INS data of CeRuSn3 reveal the presence of a broad excitation centered around 6-8 meV which is accounted by a model based on crystal electric field (CEF) excitations. On the other hand, the INS data of isostructural CeRhSn3 reveal three CEF excitations around 7.0, 12.2 and 37.2 meV. The neutron intensity sum rule indicates that the Ce ions at both cubic and tetragonal Ce sites are in Ce3+ state in both CeRuSn3 and CeRhSn3. The CEF level schemes for both the compounds are deduced. We estimate the Kondo temperature T_K = 3.1(2) K for CeRuSn3 from neutron quasielastic linewidth in excellent agreement with that determined from the scaling of magnetoresistance which gives T_K = 3.2(1) K. For CeRhSn3 the neutron quasielastic linewidth gives T_K = 4.6 K. For both CeRuSn3 and CeRhSn3, the ground state of Ce3+ turns out to be a quartet for the cubic site and a doublet for the tetragonal site.