Browsing by Author "van der Heijden, NJ"

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    Magnetic ordering in superconducting sandwiches
    (Australian Nuclear Science and Technology Organisation, 2021-11-24) Chan, A; van der Heijden, NJ; Causer, GL; Söhnel, T; Simpson, MC; Rule, KC; Lee, WTH; Bernhard, C; Mallett, BPP
    Our cuprate-manganite ‘superconducting sandwich’ multilayers exhibit a highly unusual magnetic-field induced insulating-to-superconducting transition (IST), contrary to the commonly held understanding that magnetic fields are detrimental to superconductivity [1, 2]. This new behaviour is a result of the specific magnetic and electronic properties of the manganite coupling with the high-Tc cuprate (YBa2Cu3O7-δ, YBCO). Due to the specific manganite composition, Nd0.65(Ca0.7Sr0.3)0.35MnO3 (NCSMO), we hypothesize the behaviour to originate from CE-type antiferromagnetic ordering as well as charge and orbital ordering [3]. The magnetic data presented here will focus on polarized neutron reflectometry (PNR) and elastic neutron scattering on a YBCO-NCSMO trilayer and superlattice. The model that best described the PNR data for the trilayer had antiparallel moments at the YBCO-NCSMO interfaces. In the superlattice, the direction of moments at NCSMO interfaces were found to alternate with film depth whose long-ranged ordering was broken below 35 K in a 1 T applied field. The stability of the AFM order in the superlattice was further supported by a robustness of magnetic in-plane half-order elastic scattering peaks at 9 T. This evidences the interplay of magnetism and superconductivity that play a role in realizing the IST effect in our superconducting sandwiches. © The Authors
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    Magnetic ordering in superconducting sandwiches
    (Australian Institute of Physics, 2020-02-04) Chan, A; van der Heijden, NJ; Söhnel, T; Simpson, MC; Rule, KC; Causer, GL; Lee, WT; Bernard, C; Mallett, BPP
    Our cuprate-manganite ‘superconducting sandwich’ multilayers exhibit a highly unusual magnetic-field induced insulating-to-superconducting transition, contrary to the commonly held understanding that magnetic fields are detrimental to superconductivity. This new behaviour is a result of the specific magnetic and electronic properties of the manganite coupling with the cuprate (YBa2Cu3O7-δ, YBCO). Due to the specific manganite composition, Nd0.65(Ca0.7Sr0.3)0.35MnO3 (NCSMO), we hypothesize the behaviour to originate from CE-type antiferromagnetic ordering as well as charge and orbital ordering. Zero-field cooled polarized neutron reflectometry (PNR) data in Fig 1(A) shows a sizable spin-flip (R+-) signal which may result from disordered ferromagnetic domains which sum to give a vanishing macroscopic magnetization. Initial elastic neutron scattering measurements performed on 100 nm thin film NCSMO display signatures of magnetic ordering (Fig 1(B)). Future neutron scattering measurements will look at the modification of magnetic order in a superlattice to better understand the relationship between NCSMO magnetization and our newly discovered insulating-to-superconducting transition.