Structure And Magnetic Properties Of Doped CuFeAs

It is generally known that we could adjust magnetic correlations between competing ferromagnetic?FM?and anti-ferromagnetic?AFM?correlations,which is doped by magnetic elements in iron pnictides and chalcogenides,to investigate the origin of magnetism and the mechanism of magnetism in the two-dimensional layer compounds.First,the single crystals of Cu_1-x-?Mn_xFe_1+yAs?x=0,0.10,0.22,0.40,0.54?was synthesized by arc melting method and self-flux method,on the base of newly synthesized layered iron-pnictide CuFeAs.The result indicated that Cu was doped by Mn.The Cu_1-x-?Mn_xFe_1+yAs single-crystal samples undergo a magnetic transition from FM to AFM with the increase of Mn doping,while the lattice parameters are increased.In-plane resistivity for Cu_1-x-?Mn_xFe_1+yAs single-crystal samples maintains metallic behavior in the observed temperature range?2 K-300 K?.The mechanism of the anion height controls the relative strength of these two magnetic correlations between the competing FM and AFM correlations might be more easily revealed in this paper.We may examine the mechanism of magnetism in iron pnictides and chalcogenides through investigating essential tuning parameters for varying magnetic correlations.Second,we have synthesized the newly two-dimensional layered single crystals of Ta_1-xFe_xTe₂?x=0.15,0.17,0.20?by chemical vapour transport?CVT?technique.The result implied that Ta is doped by Fe.With the increase of Fe doping,the electron carrier increased,the conductivity is enhanced,the magnetic correlation is enhanced and the metamagnetic transition to the ferromagnetic state occurred.