Muon spin relaxation study of the stripe phase order inLa1.6−xNd0.4

Abstract

We present zero-field muon spin relaxation ͑SR͒ measurements of La 1.6Ϫx Nd 0.4 Sr x CuO 4 with xϭ0.125,0.15,0.2; La 1.475 Nd 0.4 Ba 0.125 CuO 4 , La 1.875 Ba 0.125 CuO 4 , and La 1.875 Ba 0.125Ϫy Sr y CuO 4 with y ϭ0.025,0.065. All of the samples with dopant concentrations xϩyр0.15 show similar static magnetic order with coherent precession of the muon spins below T N Ϸ30 K, with a T→0 ordered Cu moment Ϸ0.3 B . The samples with xϭ0.20 show no coherent precession but manifest two distinct relaxation regimes, typical of quasistatic magnetism. We then present transverse-field SR hysteresis measurements of the La 1.45 Nd 0.4 Sr 0.15 CuO 4 and La 1.4 Nd 0.4 Sr 0.2 CuO 4 systems that show a large superconducting response below approximately 7 K and 12 K, respectively. We argue that superconductivity and magnetic order coexist in the xϭ0.15 system.

Charge segregation and antiferromagnetism in high-Tc superconductors

“…One might expect that if Zn serves to pin stripes, this effect would also be inhomogeneous. Hence, it is of interest to compare the magnetic peak intensity with that found in La 1.48 Nd 0.4 Sr 0.12 CuO 4 , where µSR has shown the magnetic order to be relatively uniform [11]. We measured the same magnetic peaks in the latter compound under identical conditions, except that we worked at a temperature of 7 K in order to avoid any significant contribution from the Nd moments.…”

Stripe order in superconducting La2−xBaxCuOHücker1, Zimmermann2, Gu3 et al. 2011Phys. Rev. B305434112View full textAdd to dashboardCite

“…For example, polycrystals have significantly lower values of T c and T SO for a given x. 5,11,28,40 Early reports on polycrystals also show somewhat lower T HT and higher T LT values. 6 Among the available single crystal data sets, we find good agreement when plotted versus the estimated actual Ba content.…”

“…Here, only TSO for x = 0.095 is from ND and TCO and TLT for x = 0.155 from XRD. trast to, e.g., the Nd 3+ ions whose large magnetic moments interact with the spins of the Cu 2+ ions in the CuO 2 planes. 39,40 Recent progress in the synthesis of La 2−x Ba x CuO 4 single crystals with x ≤ 1/8 has triggered numerous studies on the stripe order in the underdoped regime. [18][19][20][41][42][43][44][45][46][47][48][49][50] Despite previous work, however, the doping dependence of many properties requires further clarification, such as the absolute intensities of CO and SO satellite reflections, the stripe correlations between the planes, the melting of the stripe order, and the compatibility with the generic stripe phase diagram.…”

Structure and magnetic order in Fe2+xV1−xAl

“…As described in [19] the experimentally determined asymmetry A(t)is given as A(t) = A 0 G(t),where A 0 ∼ 0.21is the experimentally determined intrinsic asymmetry of the positron detectors and G(t)the normalised polarisation function of the muon ensemble implanted in the sample. In zero external field a possible source for a relaxation of the muon spin ensemble are static local magnetic fields at the muon site, B loc , due to finite electronic magnetic moments.…”

“…As described in [19] the experimentally determined asymmetry A(t)is given as A(t) = A 0 G(t),where A 0 ∼ 0.21is the experimentally determined intrinsic asymmetry of the positron detectors and G(t)the normalised polarisation function of the muon ensemble implanted in the sample.…”