We have studied Fermi surface properties of LaRhIn 5 and CeTIn (T: Co, Rh Ir) via the de Haas–van Alphen (dHvA) experiment. The a non-4 f reference compound is quasi-two dimensional, reflecting unique tetragonal crystal structure, which consistent with result FLAWP energy band calculations. an antiferromagnet CeRhIn similar to that , although cyclotron mass in roughly by one order larger than . Both surfaces are, however, different from those CeCoIn CeIrIn are well explained 4 -itinerant...

We observed de Haas-van Alphen (dHvA) oscillation in both the normal and superconducting mixed states of a heavy-fermion superconductor CeCoIn5. The Fermi surfaces are found to consist nearly cylindrical small ellipsoidal ones, reflecting unique tetragonal crystal structure. detected cyclotron masses 5-87 m0 for these extremely large, correspond large electronic specific heat coefficient about 1000 mJ K-2 mol-1. also be field dependent states.

We succeeded in growing a new transuranium compound NpPd 5 Al 2 with the tetragonal crystal structure by Pb-flux method, and measured electrical resistivity, specific heat, magnetic susceptibility magnetization. is found to be paramagnetic heavy-fermion superconductor strong coupling Δ C /γ T c = 2.33 [ =4.9 K γ= 200 mJ/(K ·mol)]. The upper critical field H c2 at 0 large highly anisotropic: (0) =37 kOe for ∥[100] =143 ∥[001]. strongly suppressed field, magnetization curve indicates step-like...

We measured the low-temperature specific heat in magnetic fields up to 80 kOe, together with magnetization for heavy-fermion superconductor CeCoIn 5 transition temperature T c = 2.25 K. is a strong-coupling large jump Δ C / n ( ) 4.7. The state significantly formed below 1 K, reaching at least 1070 mJ/K 2 ·mol fields. This electronic coefficient 0.25 K is, however, reduced increasing field, ranging from 50 kOe 820 kOe. upper critical field H c2 0 estimated be 116 ∥[100] and 49.5 ∥[001]....

The pressure dependences of the antiferromagnetic and superconducting transition temperatures have been investigated by ac heat capacity measurement under high pressures for heavy-fermion superconductor CePt 3 Si without inversion symmetry in tetragonal structure. Néel temperature T N = 2.2 K decreases with increasing becomes zero at critical P AF ≃0.6 GPa. On other hand, phase exists a wider region from ambient to about 1.5 diagram is thus very unique has never reported before heavy fermion...

Single crystals of UTe 2 were grown by the chemical transport method using iodine as agent. X-ray single crystal diffraction patterns confirmed that crystallizes in orthorhombic structure (space group I m (♯ 71)). The magnetic susceptibility is highly anisotropic, reflecting structure. effective moment µ eff = 3.2-3.7 B /U, obtained above 150 K, close to value 3.6 /U localized 5 f or 3 configurations.

We studied the pressure-induced superconductor CeIrSi$_3$ with non-centrosymmetric tetragonal structure under high pressure. The electrical resistivity and ac heat capacity were measured in same run for sample. critical pressure was determined to be $P_{\rm c}$ = 2.25 GPa, where antiferromagnetic state disappears. $C_{\rm ac}$ shows both superconducting transitions at pressures close c}$. On other hand, region is extended of up about 3.5 maximum transition temperature $T_{\rm sc}$ 1.6 K...

We succeeded in growing single crystals of LaTGe 3 (T: Fe, Co, Rh, Ir) and PrCoGe with the non-centrosymmetric tetragonal crystal structure, studied split Fermi surface properties magnitude antisymmetric spin–orbit interaction 2|α p ⊥ |. The | value is found to vary when changed from T = Rh Ir, but remains unchanged LaIrX X Si Ge. It that this large LaIrSi LaIrGe : 460 K LaCoGe , 510 LaRhGe 1100 1090 for main outer orbits named α bands 69 70 electron surfaces, example. This due effective...

High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy Fermion uranium compounds UGe2, UCoGe, URhGe, URu2Si2, UNi2Al3, UPd2Al3, UPt3 as well typical localized itinerant to understand relationship between valence state their spectral line shapes. In addition main high-binding energy satellite structure recognized in spectra of compounds, a shoulder on lower binding side lines nearly was also found. The shapes show systematic...

The crystal structure, lattice strain due to the antiferromagnetic ordering, and magnetic form factor in itinerant $5f$ compounds $\mathrm{U}T{\mathrm{Ga}}_{5}(T=\mathrm{N}\mathrm{i},\mathrm{}\mathrm{P}\mathrm{d},\mathrm{}\mathrm{Pt})$ have been studied by neutron scattering. High-resolution powder diffraction revealed that tetragonality of U-Ga layers increases down series transition metal element T. integrated intensities reflections can be well explained with N\'eel-type structure for...

We have performed a high-resolution angle resolved Ce 4$d-4f$ resonant photoemission experiment on the heavy fermion superconductor CeIrIn$_5$. observed quasi-particle band which has an energy dispersion of $\sim 30$ meV in 4$f$ on-resonance spectra. The result suggests that although spectra are dominated by localized/correlated character, small itinerant component is responsible for superconductivity this compound.

We succeeded in growing a high-quality single crystal of UFeGa 5 by the self-flux method and measured electrical resistivity, magnetic susceptibility, magnetization de Haas-van Alphen (dHvA) oscillation. Many dHvA branches were observed, ranging from 5.4×10 to 1.4×10 8 Oe. These are good agreement with theoretical ones based on f -itinerant RLAPW band calculations. The cyclotron mass is relatively large, 2.4 9.9 m 0 .

We succeeded in growing high-quality single crystals of a valence fluctuating compound YbCu 2 Si and divalent Ge . The magnetic susceptibility follows the Curie–Weiss law with Yb 3+ at high temperatures, but reveals broad peak around 40 K for H ∥[100], which is due to formation 4 f -itinerant heavy fermion state lower temperatures. This also reflected temperature dependence Hall coefficient, thermoelectric power thermal expansion. corresponding de Haas–van Alphen (dHvA) branches are...

Understanding the strange metallic behavior that develops at brink of localization in quantum materials requires probing underlying electronic charge dynamics. Using synchrotron radiation–based Mössbauer spectroscopy, we studied fluctuations metal phase β-YbAlB 4 as a function temperature and pressure. We found usual single absorption peak Fermi-liquid regime splits into two peaks upon entering critical regime. interpret this spectrum nuclear transition, modulated by nearby valence whose...

We investigated the magnetic property of typical uranium compounds by measuring susceptibility in an extended temperature range up to about 800 K. The follows Curie–Weiss law for a localized 5 f 2 -electron compound UPd 3 and ferromagnetic insulator UFe 4 P 12 . In most we observed crossover effect electrons from low-temperature itinerant nature high-temperature one. This is found be characteristic superconductors such as UGe UIr, also antiferromagnets like USb or UNiSb To assess extension...

We have carried out the de Haas–van Alphen (dHvA) experiment to clarify Fermi surface property of an antiferromagnet UPtGa 5 , and constructed magnetic phase diagram from high-field magnetization measurement. From dHvA experiment, is found consist four kinds nearly cylindrical surfaces along tetragonal [001] direction, which are approximately explained by result spin-polarized energy band calculations based on antiferromagnetic structure with a sequence (↑ ↓) [001]. Relatively large...

AbstractWe succeeded in growing high-quality single crystals of UCoGa5 and URhGa5 by the self-flux method measured electrical resistivity, magnetic susceptibility, de Hass-van Alphen(dHvA) oscillation. Three kinds dHvA branches were observed, ranging from 8.6x 105 to 8.1 x 106Oe, which correspond closed Fermi surfaces. URhGas are concluded be semimetals. The cyclotron mass is small, 0.6 m0 2.9 m0.Keywords: UCoGa5URhGa5semimetaldHvAFermi surface

We have performed angle-resolved photoemission spectroscopy $(h\ensuremath{\nu}=21.2,40.8\mathrm{eV}),$ Ce $3d\ensuremath{-}4f$ resonant $(h\ensuremath{\nu}\ensuremath{\sim}881\mathrm{eV}),$ and $3d$ x-ray absorption studies on the layered cerium compounds $\mathrm{Ce}T{\mathrm{In}}_{5}$ $(T=\mathrm{Rh}$ Ir), which show competition between superconductivity antiferromagnetism. The results suggest that $4f$ electrons in both are nearly localized. found although superconducting...

We succeeded in growing a high-quality single crystal of an antiferromagnet UPtGa 5 by the self-flux method, and measured magnetic susceptibility, electrical resistivity, specific heat de Haas–van Alphen (dHvA) oscillation. found antiferromagnetic transition at 26 K from susceptibility resistivity measurements. Six dHvA branches were observed, ranging 1.14 ×10 7 to 1.13 8 Oe. Fermi surfaces consist two nearly cylindrical spherical surfaces. The cyclotron mass is large, 10 24 m 0 , which...

We present 27 Al NMR studies for a single crystal of the newly developed superconductor NpPd 5 2 ( T c = 4.9 K). In superconducting state, spectrum shifts to lower frequencies owing decrease spin part Knight shift, and exhibits broadening characteristic local field distribution associated with vortex lattice. have also found that nuclear spin–lattice relaxation rate (1/ 1 ) decreases just below no coherence peak shows 3 behavior at low temperatures. The observed temperature dependences shift...

We have succeeded in growing a high-quality single crystal of UCu 2 Si with the tetragonal structure by Sn-flux method and measured electrical resistivity, magnetic susceptibility, magnetization specific heat. is found to order antiferromagnetically below T N =106 K, follows successive ferromagnetic ordering at C =100 K. The properties are highly anisotropic, reflecting structure. An easy-axis be [001] direction ( c -axis) both antiferromagnetic phases, while [100] corresponds hard-axis...

We succeeded in growing a high-quality single crystal of URu 2 Si by the Czochralski pulling method and applying solid state electro-transport under ultrahigh vacuum. The sample quality strongly depends on position ingot. For some parts this ingot, electrical resistivity, specific heat de Haas–van Alplhen effect were measured. resistivity surface clearly indicates T -linear temperature dependence below 5 K. mean free path was determined Alphen to be 11000 Å.

Specific heat measurements on a series of ternary compound RCu 2 Si (R: La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) single crystals have been performed by the quasi-adiabatic pulse method in wide temperature range from 0.1 to 80 K. Almost all compounds show antiferromagnetic orderings at low temperatures. We found first-order like very sharp specific peaks with R=Gd, Er. Especially, ordering DyCu is be transition. From analyses dependence magnetic entropy, we confirmed that total...

The perovskite antiferromagnetic $({T}_{\mathrm{N}}\ensuremath{\sim}220\phantom{\rule{0.28em}{0ex}}\mathrm{K})$ insulator ${\text{EuNiO}}_{3}$ undergoes at ambient pressure a metal-to-insulator transition ${T}_{\mathrm{MI}}\phantom{\rule{0.28em}{0ex}}=\phantom{\rule{0.28em}{0ex}}460\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ which is associated with simultaneous orthorhombic-to-monoclinic distortion, leading to charge disproportionation. We have investigated the change of structural and magnetic...

We have performed angle-resolved photoemission spectroscopy experiments on paramagnetic ${\mathrm{UFeGa}}_{5}$ using soft x-ray synchrotron radiation $(h\ensuremath{\nu}=500\phantom{\rule{0.3em}{0ex}}\mathrm{eV})$ and derived the bulk- U $5f$-sensitive electronic structure of ${\mathrm{UFeGa}}_{5}$. Although agreement between experimental band local density approximation calculation treating $5f$ electrons as being itinerant is qualitative, morphology Fermi surface well-explained by...