Clean-limit superconductivity in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>I</mml:mi><mml:mi>m</mml:mi><mml:mover accent="true"><mml:mn>3</mml:mn><mml:mo>¯</mml:mo></mml:mover><mml:mi>m</mml:mi></mml:mrow><mml:mo> </mml:mo><mml:mrow><mml:msub><mml:mi mathvariant="normal">H</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi></mml:mrow></mml:math> synthesized from sulfur and hydrogen donor ammonia borane
Israel Osmond, Owen Moulding, Sam Cross, Takaki Muramatsu, Annabelle Brooks, O. T. Lord, Timofey Fedotenko, Jonathan Buhot, Sven Friedemann
Abstract
We present detailed studies of the superconductivity in high-pressure ${\mathrm{H}}_{3}\mathrm{S}$. X-ray diffraction measurements show that cubic $Im\overline{3}m {\mathrm{H}}_{3}\mathrm{S}$ was synthesized from elemental sulfur and hydrogen donor ammonia borane (${\mathrm{NH}}_{3}{\mathrm{BH}}_{3}$). Our electrical transport measurements confirm superconductivity with a transition temperature ${T}_{c}=197\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ at $153\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$. From the analysis of both the normal-state resistivity and the slope of the critical field, we conclude that the superconductivity is described by clean-limit behavior. A significant broadening of the resistive transition in finite magnetic field is found, as expected for superconductors. We identify a linear temperature-over-field scaling of the resistance at the superconducting transition which is not described by existing theories.