Effects of Tin and Sulfur Chemical Substitution on the Structural and Electrical Properties of CuCr2Se4 Selenospinel

A series of CuCr2-xSnxS2.Se-3(1).(7) and CuCr2-xSnxS1.Se-7(2).(3) (x = 0.4, 0.6, and 1.0) compounds were prepared by solid-state reaction at a high temperature. Single-crystal X-ray diffraction analysis showed that CuCr1.Sn-1(0).S-9(2).Se-3(1).(7) crystallizes in a spinel-type structure (cubic Fd3 over bar m space group). The others samples were also consistent with a spinel-type structure but through powder X-ray diffraction patterns and Rietveld refinements. The systems studies showed p-type semiconductor behavior with a carrier concentration per volume of approximately ~+10(20) cm(-3). The electrical conductivity, sigma, showed tin-content dependence. The conductivity of CuCr2-xSnxS1.Se-7(2).(3) increased from ~9.0 to ~17.0 S & BULL;cm(-1) at room temperature (RT) for x = 0.4 and 0.6, respectively, and the magneto-resistance average value determined for CuCr2-xSnxS2.Se-3(1).(7) and CuCr2-xSnxS1.Se-7(2).(3) was approximately ~10(-4) omega (0.566 T, external magnetic field). DFT calculations revealed that the Cr centers concentrated most of the spin density. A smaller spin polarization featuring the opposite spin was observed for S/Se atoms.

Automated summary

A series of CuCr2-xSnxS2.Se-3(1).(7) and CuCr2-xSnxS1.Se-7(2).(3) compounds were prepared by solid-state reaction and showed a spinel-type structure. They exhibited p-type semiconductor behavior and the conductivity depended on the tin content.