11 research outputs found

    Electric field gradients in MgB2_2 synthesized at high pressure: 111^111Cd TDPAC study and ab initio calculation

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    We report the high-pressure synthesis of novel superconductor MgB2_2 and some related compounds. The superconducting transition temperature of our samples of MgB2_2 is equal to 36.6 K. The MgB2_2 lattice parameters determined via X-ray diffraction are in excellent agreement with results of our ab initio calculations. The time-differential perturbed angular correlation (TDPAC) experiments demonstrate a small increase in quadrupole frequency of 111^111Cd probe with decreasing temperature from 293 to 4.2 K. The electric field gradient (EFG) at the B site calculated from first principles is in fair agreement with EFG obtained from 11^11B NMR spectra of MgB2_2 reported in the literature. It is also very close to EFG found in our 111^111Cd TDPAC measurements, which suggests that the 111^111Cd probe substitutes for boron in the MgB2_2 lattice.Comment: 10 pages, 3 figure
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