Direct visualization of phase separation between superconducting and nematic domains in Co-doped CaFe2As2 close to a first-order phase transition
We show that biaxial strain induces alternating tetragonal superconducting and orthorhombic nematic domains in Co-substituted CaFe2As2. We use atomic force, magnetic force, and scanning tunneling microscopy to identify the domains and characterize their properties, finding in particular that tetrago...
| Autores: | , , , , , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2018 |
| País: | España |
| Recursos: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/689738 |
| Acesso em linha: | http://hdl.handle.net/10486/689738 https://dx.doi.org/10.1103/PhysRevB.97.014505 |
| Access Level: | acceso abierto |
| Palavra-chave: | First order phase transitions Microphase separation Nematic order Phase diagrams Phase transitions Phase transitions by order Quantum criticality Superconducting phase transition Superconductivity Vortices in superconductors Física |
| Resumo: | We show that biaxial strain induces alternating tetragonal superconducting and orthorhombic nematic domains in Co-substituted CaFe2As2. We use atomic force, magnetic force, and scanning tunneling microscopy to identify the domains and characterize their properties, finding in particular that tetragonal superconducting domains are very elongated, more than several tens of micrometers long and about 30 nm wide; have the same Tc as unstrained samples; and hold vortices in a magnetic field. Thus, biaxial strain produces a phase-separated state, where each phase is equivalent to what is found on either side of the first-order phase transition between antiferromagnetic orthorhombic and superconducting tetragonal phases found in unstrained samples when changing Co concentration. Having such alternating superconducting domains separated by normal conducting domains with sizes of the order of the coherence length opens opportunities to build Josephson junction networks or vortex pinning arrays and suggests that first-order quantum phase transitions lead to nanometric-size phase separation under the influence of strain |
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