Superconducting and normal-state interlayer-exchange-coupling in La$_{0.67}$Sr$_{0.33}$MnO${3}$-YBa$_{2}$Cu$_{3}$O$_{7}-La$_{0.67}$Sr$_{0.33}$ MnO${3}$ epitaxial trilayers

K. Senapati; R. C. Budhani

doi:10.1103/PhysRevB.71.224507

paper

Superconducting and normal-state interlayer-exchange-coupling in La $_{0.67}$ Sr $_{0.33}$ MnO $3$ -YBa $_{2}$ Cu $_{3}$ O $_{7} - L a$ _{0.67} $S r$ _{0.33} $M n O$ {3}$ epitaxial trilayers

arXiv:cond-mat/0504237 · doi:10.1103/PhysRevB.71.224507

Abstract

The issue of interlayer exchange coupling in magnetic multilayers with superconducting (SC) spacer is addressed in La $_{0.67}$ Sr $_{0.33}$ MnO $_{3}$ (LSMO) - YBa $_{2}$ Cu $_{3}$ O $_{7}$ (YBCO) - La $_{0.67}$ Sr $_{0.33}$ MnO $_{3}$ (LSMO) epitaxial trilayers through resistivity, ac-susceptibility and magnetization measurements. The ferromagnetic (FM) LSMO layers possessing in-plane magnetization suppress the critical temperature (T $_{c})$ of the c-axis oriented YBCO thin film spacer. The superconducting order, however, survives even in very thin layers (thickness d $_{Y} \sim$ 50 Å, $\sim$ 4 unit cells) at T $<$ 25 K. A predominantly antiferromagnetic (AF) exchange coupling between the moments of the LSMO layers at fields $<$ 200 Oe is seen in the normal as well as the superconducting states of the YBCO spacer. The exchange energy J $_{1}$ ( $\sim$ 0.08 erg/cm $^{2}$ at 150 K for d $_{Y}$ = 75 Å) grows on cooling down to T $_{c}$ , followed by truncation of this growth on entering the superconducting state. The coupling energy J $_{1}$ at a fixed temperature drops exponentially with the thickness of the YBCO layer. The temperature and d $_{Y}$ dependencies of this primarily non-oscillatory J $_{1}$ are consistent with the coupling theories for systems in which transport is controlled by tunneling. The truncation of the monotonic T dependence of J $_{1}$ below T $_{c}$ suggests inhibition of single electron tunneling across the CuO $_{2}$ planes as the in-plane gap parameter acquires a non-zero value.

Accepted for publication in Phys. Rev. B

Superconducting and normal-state interlayer-exchange-coupling in La $_{0.67}$ Sr $_{0.33}$ MnO $3$ -YBa $_{2}$ Cu $_{3}$ O $_{7} - L a$ _{0.67} $S r$ _{0.33} $M n O$ {3}$ epitaxial trilayers

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Superconducting and normal-state interlayer-exchange-coupling in La0.67​Sr0.33​MnO3-YBa2​Cu3​O7​−La_{0.67}Sr_{0.33}MnO{3}$ epitaxial trilayers

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Cited by in corpus (11)

Superconducting and normal-state interlayer-exchange-coupling in La $_{0.67}$ Sr $_{0.33}$ MnO $3$ -YBa $_{2}$ Cu $_{3}$ O $_{7} - L a$ _{0.67} $S r$ _{0.33} $M n O$ {3}$ epitaxial trilayers