arXiv subjects

Chaoguo Wang

Publications and source records attributed to Chaoguo Wang.

5 recordsLinked to original sources

arXiv2026

A d-Electron Heavy-Fermion-Like Superconductor with Frustration-Induced Flat Bands

Heavy-fermion superconductors are mostly associated with f-electron materials with Kondo lattices, while known d-electron heavy-fermion-like systems are often linked to orbital-selective local moments, Hund-metal physics, or a charge-density-wave mechanism. Here we report Mo4PtGa17, a noncentrosymmetric itinerant d-electron superconductor with a geometrically frustrated breathing-pyrochlore Mo lattice. Thermodynamic, transport and NMR measurements reveal heavy-fermion-like behavior superconductivity and dominant ferromagnetic spin fluctuations near a ferromagnetic instability. Theoretical calculations identify nearly flat bands, van Hove singularities and Kramers nodal lines near the Fermi energy, derived intrinsically from Mo-4d states and are robust against on-site electronic correlations. These results suggest that the geometrically frustrated lattice in Mo4PtGa17 generates an intriguing electronic structure that enhances the density of states, spin susceptibility and quasiparticle mass. Mo4PtGa17 therefore identifies a unique route to heavy-fermion-like superconductivity in d-electron materials through geometrical frustration, different from the previously reported systems.

cond-mat.str-el↗

arXiv2026

Magnetic Anisotropy and Metamagnetic Transitions in Er3Pt2Sb4.55 with A Distorted Square Net Lattice

Magnetic materials with square-net sublattices are of great interest due to its potential to realize magnetic frustration. Here we report the crystal growth and structural, magnetic, thermodynamic and electronic transport properties of a new rare-earth-based intermetallic compound, Er3Pt2Sb4.55(5). The new material possesses a distorted square-net framework of Er. Magnetic properties measurements suggest anisotropic behavior, long-range antiferromagnetic ordering and metamagnetic transitions based on a Jeff = 1/2 Er3+ motif. A magnetic structure is proposed based on the observed magnetic and thermodynamic properties. This new material expands the R3Pt2Sb4+x family with distorted square-net lattice of rare-earth elements and offers a new opportunity to study the relationship between magnetic ordering, crystal-electric field effect and crystal structure in rare-earth-based compounds.

cond-mat.mtrl-sci↗

arXiv2026

Layered CrGe1-xSe3+y with Cr Kagome Lattice and Antiferromagnetic Ordering

We report the synthesis and properties of a new layered material, CrGe1-xSe3+y. The crystal structure was determined by using single crystal x-ray diffraction and transmission electron microscopy. CrGe1-xSe3+y crystallizes with a space group R-3m, featuring a double Kagome layer of chromium atoms, sandwiched between disordered Ge-Se layers. This compound displays antiferromagnetic order below 50 K, unlike the ferromagnetic behavior in CrGeTe3. Chromium displays an effective moment of ~3.9 {\mu}B/Cr, consistent with Cr3+ oxidation. The presence of this phase limits the possibility of a ferromagnetic CrGeSe3 analogous to CrGeTe3.

cond-mat.mtrl-sci↗

arXiv2024

Evolution of Ferromagnetism and Electrical Resistivity in Sb-Doped Cr4PtGa17

We describe the doping effects on a metallic breathing pyrochlore compound, Cr4PtGa17. Upon doping with Sb, i.e., Cr4Pt(Ga1-xSbx)17, it was found that a selective doping on one of the seven Ga sites occurs. With increasing dopant level, the ferromagnetism in the parent compound is gradually suppressed, along with a decrease in fitted Curie-Weiss temperature (from 61 (1) K to -1.8 (1) K) and effective moment (from ~2.26 muB/f.u. to ~0.68 muB/f.u.). Low-temperature heat capacity measurements confirm the absence of magnetic ordering above 0.4 K for the three most doped samples. Meanwhile, electrical resistivity measurements display a metal-semiconductor transition with increasing Sb contents, which is attributed to an increase of Fermi energy based on the calculations of electronic band structure and density of states. Moreover, we have speculated that the ferromagnetism in Cr4PtGa17 is governed by itinerant electrons according to our observations. This study of Sb-doping effect on Cr4PtGa17 provides deeper understanding of magnetism of this system and possibilities for future modifications.

cond-mat.mtrl-sci↗

arXiv2024

Crystallographic Disorder and Strong Magnetic Anisotropy in Dy3.1Pt2.0Sb3.8

We report the crystal growth and characterization of a rare-earth-containing material, Dy3.00(1)Pt2Sb4.48(2). This compound possesses a similar structure to the previously reported Y3Pt4Ge6, but lacks two layers of Pt atoms. Crystallographic disorder was found in Dy3.00(1)Pt2Sb4.48(2). Additionally, the Dy-Dy framework was found to have both square net and triangular lattices. Dy3.00(1)Pt2Sb4.48(2)8 was determined to be antiferromagnetically ordered around ~15 K while a competing antiferromagnetic sublattice also exists at lower temperature. Strong magnetic anisotropy was observed and several metamagnetic transitions were seen in the hysteresis loops. Furthermore, the Curie-Weiss fitting revealed unusually small effective moment of Dy, which is far below the expected value of Dy3+ (10.65 muB). This material might provide a new platform to study the relation between crystallographic disorder and magnetism.

cond-mat.mtrl-sci↗