Superconductivity at 60 K in La2-xSrxCaCu2O6: the simplest double-layer cuprate

Structural and magnetic instabilities ofLa2−xSrxCaCuUlrich1, Kondo2, Reehuis3 et al. 2002Phys. Rev. B130120View full textAdd to dashboardCite

“…The resulting lattice parameters, atomic coordinates and isotropic temperature factors are listed in Table I and are in good agreement with those of previous reports [11][12][13]; further details will be reported elsewhere. At 10 K, however, weak additional (and hitherto unobserved) reflections were found, as shown in Fig.…”

“…LSCCO has thus been termed the simplest bilayer cuprate [11]. We report the discovery of an unexpected low temperature tetragonal-to-orthorhombic transition in undoped and doped LSCCO.…”

Growth and structural characterization of large superconducting crystals of La2−xCa1+xCu2O6<

“…In principle, we could achieve p opt by using sufficient Ca, adding excess oxygen, or using a combination of these components. If we consider the composition originally studied by Cava et al [4,37], La 1.6 Sr 0.4 CaCu 2 O 6+δ with δ ∼ −0.07, application of our formula gives p = 0.13, which is in the vicinity of p opt . There, the doping by excess alkalineearth ions was partially offset by oxygen vacancies.…”

“…While suitable crystals of La 2−x Sr x CaCu 2 O 6 (La-Sr-2126) [1] as well as La 2−x Ca 1+x Cu 2 O 6 (La-Ca-2126) [2] have been grown previously and studied by neutron diffraction [1,3], those samples exhibited little to no superconductivity. Obtaining crystals with a large superconducting volume fraction has been a challenge, because synthesis of superconducting samples requires annealing in high-pressure oxygen [4]. We have finally been able to achieve this last step, and in this paper we describe the synthesis conditions and magnetic and structural characterizations of the resulting crystals.…”

“…Following the discovery of superconductivity in La 2−x Ba x CuO 4 [6], Torrance et al [7] reported on the metallic, but non-superconducting, character of La 2 SrCu 2 O 6.2 , followed by crystallographic studies of LaCa-2126 [8] and La 2 SrCu 2 O 6 [9]. It was not long before Cava et al [4] announced the discovery of superconductivity with a transition temperature, T c , of ∼ 60 K in La-Sr-2126; the key here was to anneal in high-pressure oxygen. Numerous studies of synthesis conditions and superconductivity in La-Sr-2126 [10,11] and La-Ca-2126 [12][13][14][15] quickly followed.…”