Incommensurate Spin Ordering and Fluctuations in underdoped La_{2-x}Ba_{x}CuO_{4}

Abstract

Using neutron scattering techniques, we have studied incommensurate spin ordering as well as low energy spin dynamics in single crystal underdoped \LBCO with x$\sim$0.095 and 0.08; high temperature superconductors with T${}_C\sim$ 27 K and 29 K respectively. Static two dimensional incommensurate magnetic order appears below T${}_N$=39.5 $\pm$ 0.3 K in \LBCO (x=0.095) and a similar temperature for x=0.08 within the low temperature tetragonal phase. The spin order is unaffected by either the onset of superconductivity or the application of magnetic fields of up to 7 Tesla applied along the c-axis in the x=0.095 sample. Such magnetic field {\it independent} behaviour is in marked contrast with the field induced enhancement of the staggered magnetisation observed in the related \LSCO system, indicating this phenomenon is not a universal property of cuprate superconductors. Surprisingly, we find that incommensurability $\delta$ is only weakly dependent on doping relative to \LSCO. Dispersive excitations in \LBCO (x=0.095) at the same incommensurate wavevector persist up to at least 60 K. The dynamical spin susceptibility of the low energy spin excitations saturates below \tc, in a similar manner to that seen in the superconducting state of La${}_2$CuO${}_{4+y}$.

9 pages, 7 figures, submitted to PRB, figures updated

References in corpus (3)

• Magnetic neutron scattering in hole doped cuprate superconductors
• Stripeless incommensurate magnetism in a doped strongly correlated oxide
• High resolution X-ray scattering studies of structural phase transitions in underdoped La${}_{2-x}$Ba${}_x$CuO${}_4$

Cited by in corpus (5)

• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Striped superconductors: How the cuprates intertwine spin, charge and superconducting orders
• Evidence for unusual superconducting correlations coexisting with stripe order in La(1.875)Ba(0.125)CuO(4)
• Magnetic field induced enhancement of spin-order peak intensity in La(1.875)Ba(0.125)CuO(4)
• Diagonal and Collinear Incommensurate Spin Structures in underdoped La${}_{2-x}$Ba${}_x$CuO${}_4$