Crystal Chemical Substitutions of YBa2Cu3O7-d to Enhance Flux Pinning (Postprint)

A review of the physical properties and principles of chemical substitution of YBCO to enhance flux pinning was provided. Chemical substitution is a potential cost-effective method of introducing nano-size defections into the superconductor to provide significant enhancement of Jc. It is especially important to consider this as a method for flux pinning to achieve ultra-small defects 1-4 nm in size, that were show in this paper to be essential to realize pinning for ultra-high magnetic fields 15 Tesla. While a significant number of studies have been done in this field, large gaps of knowledge still exist in the literature on the effect of RE substitution on Jc and pinning of YBCO. Initial studies indicate a consistent trend that substitution of 0.25 molar fraction of RE for Y or Y for RE provides significant increase of low-field Jc.