A new ternary Mg_(1.4)Co_(21.6)B_(6) compound in the Mg-Co-B system was synthesized via a conventional solid-state reaction method and the effect of Ni-substitution on its crystal structure,thermal stability,solid sol...A new ternary Mg_(1.4)Co_(21.6)B_(6) compound in the Mg-Co-B system was synthesized via a conventional solid-state reaction method and the effect of Ni-substitution on its crystal structure,thermal stability,solid solubility and physical properties were systematically investigated.The crystal structure of the Mg_(1.4)Co_(21.6)B_(6) compound was fully determined by the X-ray diffraction technique with Rietveld refinement method.It is found that Mg_(1.4)Co_(21.6)B_(6) crystallizes in the form of C_(6)Cr_(23) structure type(space group:Fm-3m(No.225),a=10.5617(2)A,Z=4).The results showed that the 4a sites have been occupied completely by Co atoms in present compound which with M_(2-x)Ni_(21+x)B_(6) form belonging to the W_(2)Cr_(21)C_(6)-type.When Mg_(1.4)Co_(21.6)B_(6) is repeatedly sintered at elevated temperatures,it becomes unstable and decomposes into Co3B and Mg.The lattice parameters of the Mg_(1.4)Co_(21.6)B_(6) solid solution alters dramtically with increasing Ni substitution,with no regular trend being observed.The electrical and magnetic performances of the 3.6Mg:3Co:17Ni:6B and 3.6Mg:3Co:18Ni:6B(nominal compositions)samples suggest that both samples are typical ferromagnetic materials.The temperature in the maximum drop of theρ(T)curve decreases as a function of the Ni content.Base on the correlation between the critical temperature and Ni content,a linear fitting equation is obtained and the critical temperature of Mg_(1.4)Co_(21.6)B_(6) calculated utilizing the linear fitting equation.The findings in this work may provide certain reference values for material science on electrical magnetic properties and other references for researching the material further.展开更多
基金China’s Sichuan Science and Technology Program(2019YJ0441)Chengdu Normal University First-class Discipline Construction Major Scientific Research Projects(CS18ZDZ03)+1 种基金Chengdu Normal University Talent introduction scientificresearch special project(YJRC2015-3)The National Natural Science Foundation of China(11647095,51708143,22076034)。
文摘A new ternary Mg_(1.4)Co_(21.6)B_(6) compound in the Mg-Co-B system was synthesized via a conventional solid-state reaction method and the effect of Ni-substitution on its crystal structure,thermal stability,solid solubility and physical properties were systematically investigated.The crystal structure of the Mg_(1.4)Co_(21.6)B_(6) compound was fully determined by the X-ray diffraction technique with Rietveld refinement method.It is found that Mg_(1.4)Co_(21.6)B_(6) crystallizes in the form of C_(6)Cr_(23) structure type(space group:Fm-3m(No.225),a=10.5617(2)A,Z=4).The results showed that the 4a sites have been occupied completely by Co atoms in present compound which with M_(2-x)Ni_(21+x)B_(6) form belonging to the W_(2)Cr_(21)C_(6)-type.When Mg_(1.4)Co_(21.6)B_(6) is repeatedly sintered at elevated temperatures,it becomes unstable and decomposes into Co3B and Mg.The lattice parameters of the Mg_(1.4)Co_(21.6)B_(6) solid solution alters dramtically with increasing Ni substitution,with no regular trend being observed.The electrical and magnetic performances of the 3.6Mg:3Co:17Ni:6B and 3.6Mg:3Co:18Ni:6B(nominal compositions)samples suggest that both samples are typical ferromagnetic materials.The temperature in the maximum drop of theρ(T)curve decreases as a function of the Ni content.Base on the correlation between the critical temperature and Ni content,a linear fitting equation is obtained and the critical temperature of Mg_(1.4)Co_(21.6)B_(6) calculated utilizing the linear fitting equation.The findings in this work may provide certain reference values for material science on electrical magnetic properties and other references for researching the material further.
