Magnetic signatures of 120 K superconductivity at interfaces in La₂CuO_4+δ

Abstract

In self-assembled vertically aligned nanocomposite (VAN) thin films of La2CuO4+δ + LaCuO3, we find from DC magnetic susceptibility measurements, weak signatures of superconductivity at ∼120 K.

Materials Informatics Reveals Unexplored Structure Space in Cuprate Superconductors

“…A key limitation is that due to Poisson effects such methods influence both the a and c-lattice parameters preventing the exploration of trends in a one-factor-at-a-time manner. Recently, new experiments have shown that it is possible to tune the a and c-lattice parameters independently allowing for unexplored regions of the materials space to be investigated; [7,8] this vertically aligned nanocomposite (VAN) approach has led to enhanced Tcs of 50 K [7] and up to ≈120 K from magnetic measurements [8] in nano-engineered La 2 CuO 4−δ films relative to 40 K in the bulk (These points are highlighted in Figure 3E-see Experimental Section for how the apical distances for these samples were estimated). These examples support the hypothesis that the unexplored region may yield higher Tc systems.…”

“…However, the out‐of‐plane lattice parameter is not fixed and it responds elastically to the in‐plane strain. Recently, experimental techniques based on nano‐engineering [ 7,8 ] have been reported that enable independent tuning of lattice distances. These techniques open up new experimental pathways to increase Tc through the exploitation of structure–function relationships.…”

“…A large region (labeled 'unexplored region") of high apical Cu-O distance and low in-plane Cu-O distance is apparent.Experiments that probe this region are likely to provide useful insight into the nature of Tc-structure trends in cuprates. We highlight the vertically aligned nanocomposite (VAN) samples from[7,8] as examples of nano-engineering approaches to investigate the region. In the key VAN c-214/a-113 refers to the La 2 CuO 4−δ /LaCuO 3 interface from[7] and VAN c-214/a-214 refers to the c-aligned La 2 CuO 4−δ /a-aligned La 2 CuO 4−δ interface from ref [8]…”

“…We highlight the vertically aligned nanocomposite (VAN) samples from[7,8] as examples of nano-engineering approaches to investigate the region. In the key VAN c-214/a-113 refers to the La 2 CuO 4−δ /LaCuO 3 interface from[7] and VAN c-214/a-214 refers to the c-aligned La 2 CuO 4−δ /a-aligned La 2 CuO 4−δ interface from ref [8]…”

High Yield Transfer of Clean Large-Area Epitaxial Oxide Thin Films

“…Functional oxide thin films are of great interest for their broad spectrum of physical properties, e.g. in dielectrics and ferroelectrics [ 1 , 2 ], magnetics [ 3 , 4 ], superconductors [ 5 , 6 ], ionic conductors [ 7 , 8 ], photovoltaics [ 9 , 10 ], resistive switching [ 11 , 12 ], etc. Furthermore, with the rapid development of two-dimensional (2D) materials and van der Waals heterostructures in the last decades, it is highly anticipated that exemplary functionalities will be achieved from low-dimensional, single-crystalline functional oxide thin films, particularly on flexible and semiconductor substrates [ 13 ].…”