Crystal growth, magnetic and electrical transport properties of the kagome magnet RCr_(6)Ge_(6)(R= Gd–Tm)

Kagome magnets have attracted considerable research attention due to the interplay between topology,magnetism and electronic correlations.In this study we report single-crystal synthesis of a series of the kagome magnets.RCr_(6)Ge_(6)(R=Gd-Tm) that possess defect-free Cr kagome lattices and systematically study their magnetic and electrical transport properties.The transition from a canted ferrimagnetic to a paramagnetic state in GdCr_(6)Ge_(6),TbCr_(6)Ge_(6),DyCr_(6)Ge_(6),HoCr_(6)Ge_(6),ErCr_(6)Ge_(6) and TmCr_(6)Ge_(6) occurs at 11.3 K,10.8 K,4.3 K,2.5 K,3.3 K and below 2 K,respectively,due to R-R interactions within the compounds.Magnetization measurements reveal highly anisotropic magnetism with canted magnetic moments in these compounds.In electrical transport,both negative and positive magnetoresistances at different magnetic fields and temperatures have been observed due to the competition between different scattering mechanisms.This work enriches our understanding of the Cr-based kagome magnets and paves the way to search for possible topological responses in this family.

Nonreciprocal transport in the superconducting state of the chiral crystal NbGe_(2)

Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields,can give rise to directional dichroism of the electrical transport phenomena via the magnetochiral anisotropy.In this study,we investigate the nonreciprocal magneto-transport in microdevices of NbGe_(2),a superconductor with structural chirality.A giant nonreciprocal signal from vortex motions is observed during the superconducting transition,with the ratio of nonreciprocal resistance to the normal resistanceγreaching 6×10^(5)T^(-1)·A^(-1).Interestingly,the intensity can be adjusted and even sign-reversed by varying the current,the temperature,and the crystalline orientation.Our findings illustrate intricate vortex dynamics and offer ways of manipulation on the rectification effect in superconductors with structural chirality.

Bioeffects of Microgravity and Hypergravity on Animals

Gravity alterations in space cause significant adaptive effects on the human body,including changes to the muscular,skeletal,and vestibular systems.However,multiple factors besides gravity exist in space;therefore,it is difficult to distinguish gravity-related bioeffects from those of the other factors,including radiation.Although everything on the Earth surface is subject to gravity,gravity-induced effects are not explicitly clear.Here,different research methods that have been used in gravity alterations,including parabolic flight,diamagnetic levitation,and centrifuge,are reviewed and compared.The bioeffects that are reported to be associated with altered gravity in animals are summarized,and the potential risks of hypergravity and microgravity are discussed,with a focus on microgravity,which has been studied more extensively.It should be noted that although various microgravity and hypergravity research methods have their limitations,such as the inevitable magnetic field effects in diamagnetic levitation and short duration of parabolic flight,it is evident that ground-based clinical,animal,and cellular experiments that simulate gravity alterations have served as important and necessary complements to space research.These researches not only provide critical and fundamental biological information on the effects of gravity from biomechanics and the biophysical perspectives,but also help in developing future countermeasures for astronauts.

Critical behavior in the itinerant ferromagnet SmMn_(2)Ge_(2)

Transition metal and rare earth intermetallics have been a fertile playground for research of various quantum states.We report detailed magnetic studies on Sm Mn_(2)Ge_(2),an anisotropic itinerant magnet with multiple magnetic phases.The critical behavior of the ferromagnetic phase transition is investigated by employing the modified Arrott plot with the Kouvel-Fisher method.The critical temperature TCis determined to be around 342.7 K with critical exponents ofβ=0.417 andγ=1.122,and the interaction function is found to be J(r)~r^(-4.68),suggesting the coexistence of long-range and shortrange magnetic interactions.Our results contribute to the understanding of complex magnetism in Sm Mn_(2)Ge_(2),which may provide fundamental guidance in future spintronic applications.