The field‐angle dependence of the critical current in a REBa_(2)Cu_(3)O_(7) coated conductor has been measured over a fine range of temperatures from 15 K to 80 K.The particular sample is demonstrated to have a very ...The field‐angle dependence of the critical current in a REBa_(2)Cu_(3)O_(7) coated conductor has been measured over a fine range of temperatures from 15 K to 80 K.The particular sample is demonstrated to have a very low fraction of extrinsic planar defects by its near‐isotropic critical current at 77 K.At a representative magnetic field of 3 T we are able to track the emergence of the ab‐plane peak usually associated with intrinsic pinning and quantify its evolution with temperature by fitting to a maximum‐entropy function.We are also able to observe the evolution of dip and peak features in the angle dependence of the power‐law index n with decreasing temperature and show that a dip appearing at 65 K is supplanted by a sharper positive peak from 50 K.The combination of critical current and power‐law index temperature dependences shows the onset of intrinsic pinning at 50 K.展开更多
基金supported by the Royal Society of New Zealand under Marsden Fund Grant VUW1805.
文摘The field‐angle dependence of the critical current in a REBa_(2)Cu_(3)O_(7) coated conductor has been measured over a fine range of temperatures from 15 K to 80 K.The particular sample is demonstrated to have a very low fraction of extrinsic planar defects by its near‐isotropic critical current at 77 K.At a representative magnetic field of 3 T we are able to track the emergence of the ab‐plane peak usually associated with intrinsic pinning and quantify its evolution with temperature by fitting to a maximum‐entropy function.We are also able to observe the evolution of dip and peak features in the angle dependence of the power‐law index n with decreasing temperature and show that a dip appearing at 65 K is supplanted by a sharper positive peak from 50 K.The combination of critical current and power‐law index temperature dependences shows the onset of intrinsic pinning at 50 K.
