arXiv subjects

Kaizhen Guo

Publications and source records attributed to Kaizhen Guo.

3 recordsLinked to original sources

arXiv2024

1/3 and other magnetization plateaus in a quasi-one-dimensional Ising magnet $\mathbf{TbTi_3Bi_4}$ with zigzag spin chain

We report the magnetic properties of newly synthesized, single crystals of $\mathrm{TbTi_3Bi_4}$ whose crystal structure is highlighted by the stacking of terbium-based zigzag chains and titanium-based kagome lattices. This compound demonstrates extreme easy-axis magnetic anisotropy due to the crystalline-electric-field effect which aligns the $\mathrm{Tb^{3+}}$ moments along the zigzag chain direction. As the result of the strong single-ion anisotropy and multiple magnetic interactions, $\mathrm{TbTi_3Bi_4}$ behaves as a quasi-one-dimensional Ising magnet with a remarkable antiferromagnetic ordering at $T_\mathrm{N}$ = 20.4 K. When a magnetic field is applied along the direction of the zigzag chain, multiple meta-magnetic transitions occur between 1/3 and other magnetization plateaus. We have created a field-temperature phase diagram and mapped out the complex magnetic structures resulting from frustration.

cond-mat.str-el↗

arXiv2023

Ferromagnetic half levitation of LK-99-like synthetic samples

We successfully synthesized polycrystalline LK-99-like ceramic samples with a solid-state-sintering method. Powder X-ray diffraction shows that the main contents are $\mathrm{Pb_{10-x}Cu_x(PO_4)_6O}$ and $\mathrm{Cu_2S}$, consistent with recent reports [arXiv:2307.12037; arXiv:2308.01192]. In some small flaky fragments, we successfully observed ``half levitation'' atop a $\mathrm{Nd_2Fe_{14}B}$ magnet. Using magnetization measurements on such small pieces, as well as on a large piece which does not exhibit the half levitation, we show that the samples ubiquitously contain weak yet definitive soft ferromagnetic components. We argue that, together with the pronounced shape anisotropy of the small fragments, the soft ferromagnetism is sufficient to explain the observed half levitation in strong vertical magnetic fields. Our measurements do not indicate the presence of the Meissner effect, nor zero resistance, in our samples, leading us to believe that our samples do not exhibit superconductivity. The precise chemical composition and the physics behind the ferromagnetic component remain outstanding questions to be addressed in future research.

cond-mat.supr-con↗

arXiv2022

Triangular Kondo lattice in $\mathrm{YbV_6Sn_6}$ and its quantum critical behaviors in magnetic field

We report magnetization, heat capacity and electrical resistivity for a newly discovered heavy fermion (HF) compound $\mathrm{YbV_6Sn_6}$ which is crystallized in a hexagonal $\mathrm{HfFe_6Ge_6}$-type structure, highlighted by the stacking of triangular ytterbium sublattice and kagome vanadium sublattice. Above 2 K, $\mathrm{YbV_6Sn_6}$ shows typical HF properties due to the Kondo effect on the Kramers doublet of $\mathrm{Yb^{3+}}$ ions in crystal electric field. A remarkable magnetic ordering occurs at $T_{\mathrm{N}}$ = 0.40 K in zero field while a weak external field suppresses the ordering and induces non-Fermi liquid (NFL) behavior. In strong magnetic field the compound shows a heavy Fermi liquid state. $\mathrm{YbV_6Sn_6}$ presents as one of the few examples of Yb-based HF compounds hosting triangular Kondo lattice on which a magnetic field induces quantum criticality near zero temperature.

cond-mat.str-el↗