High quality single crystal ZrSiS as a theoretically predicted Dirac semimetal has been grown successfully using a vapor phase transport method. The single crystals of tetragonal structure are easy to cleave into perfect square-shaped pieces due to the van der Waals bonding between the sulfur atoms of the quintuple layers. Physical property measurement results including resistivity, Hall coefficient (RH), and specific heat are reported. The transport and thermodynamic properties suggest a Fermi liquid behavior with two Fermi pockets at low temperatures. At T = 3 K and magnetic field of Hǁc up to 9 Tesla, large magneto-resistance up to 8500% and 7200% for Iǁ(100) and Iǁ(110) were found. Shubnikov de Haas (SdH) oscillations were identified from the resistivity data, revealing the existence of two Fermi pockets at the Fermi level via the fast Fourier transform (FFT) analysis. The Hall coefficient (RH) showed hole-dominated carriers with a high mobility of 3.05 × 104 cm2 V−1 s−1 at 3 K. ZrSiS has been confirmed to be a Dirac semimetal by the Dirac cone mapping near the X-point via angle resolved photoemission spectroscopy (ARPES) with a Dirac nodal line near the Fermi level identified using scanning tunneling spectroscopy (STS).

We report the single crystal growth and superconducting properties of a misfit layered (SnS)1.15(TaS2) compound. The transport, magnetic, and thermodynamic properties revealed the superconducting transition with an onset temperature of T c ∼ 3.01 K. The high resolution transmission electron microscopy (HRTEM) image clearly shows the misfit stacking of SnS and TaS2 layers. Based on the Werthamer–Helfand–Hohenberg (WHH) formula and Ginzburg–Landau theory, the upper critical fields are H c2(0) = 0.64 ± 0.06 T and 0.22 ± 0.02 T with coherence lengths of ξ = 22.67 and 38.68 nm for field applied perpendicular (H ⊥) and parallel (H //) to the plane, respectively. On the basis of the specific heat measurement data analysis of derived parameters including Sommerfeld coefficient γ = 5.831 ± 0.012 mJ mol–1 K–2, Debye temperature Θ D = 151 K, specific heat jump ΔC e /γT c = 0.812, and electron–phonon coupling constant λ el–ph ∼ 0.724, all indicate the weak-coupling nature for (SnS)1.15(TaS2) as a misfit layered superconductor. Resistivity measurements show that T c increases from temperature 3.01 to 3.85 K at 1.95 GPa, and linear dependence of T c as a function of pressure (P) is observed up to 1.583 GPa.

In the asymmetric unit of the title mol­ecular salt, C6H9N2 +·C2Cl3O2 −, there are two independent 2-amino-6-methyl­pyridinium cations and two independent tri­chloro­acetate anions. The pyridine N atom of the 2-amino-6-methyl­pyridine mol­ecule is protonated and the geometries of these cations reveal amine–imine tautomerism. Both protonated 2-amino-6-methyl­pyridinium cations are essentially planar [maximum deviations = 0.026 (2) and 0.012 (2) Å]. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl­ate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. These motifs are connected via N—H⋯O and C—H⋯O hydrogen bonds to form slabs parallel to (101).

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We report the single crystal growth and transport properties of a Weyl semimetal TaAs. Unsaturated large magnetoresistance of about 22 100% at 2 K and 9 T is observed. From the Hall measurement, carrier concentrations n  =  4.608  ×  10 m and p  =  3.099  ×  10 m, and mobilities µ =  2.502 m V s and µ =  16.785 m V s at 2 K are extracted. The de Haas-van Alphen oscillations at 2 K and 9 T suggest the presence of a Fermi surface, and the quantum electronic parameters such as effective cyclotron mass and Dingle temperature were obtained using Lifshitz-Kosevich fitting. Temperature dependent resistivity measurements at different static magnetic fields suggest the formation of an insulating gap in the Weyl semimetal TaAs. An angle-resolved photoemission spectroscopy study reveals Fermi arc surface states with different shaped features such as a long elliptical contour around each [Formula: see text] point, a bowtie-shaped contour around each [Formula: see text] point, and a crescent-shaped feature near the midpoint of each [Formula: see text] line.