By substituting Fe with the 5d-transition metal Pt in BaFe2As2, we have successfully synthesized the superconductors BaFe2−xPtxAs2. The systematic evolution of the lattice constants indicates that the Fe ions were successfully replaced by Pt ions. By increasing the doping content of Pt, the antiferromagnetic order and structural transition of the parent phase is suppressed and superconduc-tivity emerges at a doping level of about x = 0.02. At a doping level of x = 0.1, we get a maximum transition temperature Tc of about 25 K. While even for this optimally doped sample, the residual resistivity ratio (RRR) is only about 1.35, indicating a strong impurity scattering effect. We thus argue that the doping to the Fe-sites naturally leads to a high level impurity scattering, although the superconductivity can still survive at about 25 K. The synchrotron powder x-ray diffraction shows that the resistivity anomaly is in good agreement with the structural transition. The super-conducting transitions at different magnetic fields were also measured at the doping level of about x = 0.1, yielding a slope of-dHc2/dT = 5.4 T/K near Tc. Finally a phase diagram was established for the Pt doped 122 system. Our results suggest that superconductivity can also be easily induced in the FeAs family by substituting the Fe with Pt, with almost the similar maximum transition temperatures as doping Ni, Co, Rh and Ir.

In the design of absorbing materials, investigating the ideal value range of electromagnetic parameters under given conditions and adjusting the electromagnetic parameters by existing materials to achieve the ideal range need are two important issues to be solved. Based on transmission line theory and Debye theory, numerical simulations are used to explore the ideal value range of various parameters of absorbing materials under different conditions as well as their selection laws. The Cole-Cole diagram based on combining theory and experiments was given for optimizing design of absorption performance. When the thickness and reflection attenuation rate of the material are presupposed, the real and imaginary parts of the corresponding ideal permittivity should form an approximately elliptic curve. When the permittivity of the material is in the elliptical region, the reflection attenuation rate is lower than its given value. Ellipses with lower reflection attenuation locate in ellipses with higher reflection attenuation, but the centers of the ellipses do not coincide. As the reflection attenuation rate decreases, the corresponding ellipse area shrinks sharply, and the range of electromagnetic parameters becomes rigorous.