We studied how the electronic, superconducting, and magnetic properties of $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_7/\mathrm{N}{\mathrm{d}}_{1-x}{\left(\mathrm{C}{\mathrm{a}}_{1-y}\mathrm{S}{\mathrm{r}}_y\right)}_x\mathrm{Mn}{\mathrm{O}}_3$ multilayers depend on the tolerance factor and the hole doping of the manganite. In particular, we investigated the granular superconducting state and the related magnetic-field-driven insulator-to-superconductor transition that was previously discovered in corresponding multilayers with $\mathrm{P}{\mathrm{r}}_{0.5}\mathrm{L}{\mathrm{a}}_{0.2}\mathrm{C}{\mathrm{a}}_{0.3}\mathrm{Mn}{\mathrm{O}}_3$ [B. P. P. Mallett et al., Phys. Rev. B 94, 180503(R) (2016)]. We found that this granular superconducting state occurs only when the manganite layer is in a charge/orbital ordered and CE-type antiferromagnetic state (Mn-CO/OO). The coupling mechanism underlying this intriguing proximity effect seems to involve the domain boundaries of the Mn-CO/OO and/or the charge disordered regions of the manganite layer that become more numerous as the hole doping is reduced below $x=0.5$.

• Received 26 April 2019
• Revised 17 June 2019

DOI:https://doi.org/10.1103/PhysRevMaterials.3.084801