Related papers: Field-induced structural evolution in the spin-Pei…
CuGeO$_3$ has long been studied as a prototypical example of the spin-Peierls transition in a $S = 1/2$ Heisenberg chain. Despite intensive investigation of this quasi-one-dimensional material, systematic measurements and calculations of…
Polarized far-infrared (FIR) spectroscopic measurements and FIR magneto-optical studies were performed on the inorganic spin-Peierls compound CuGeO_3. An absorption line, which was found at 98 cm$^{-1}$ in the dimerized phase (D phase), was…
Using single crystal neutron scattering we show that the magnetic structure Ni$_3$TeO$_6$ at fields above 8.6 T along the $c$ axis changes from a commensurate collinear antiferromagnetic structure with spins along c and ordering vector…
ESR-study of the Ni-doped spin-Peierls compound CuGeO3 has been performed in the frequency range 9-75 GHz. At low temperatures the g-factor is smaller than the value expected for Cu- and Ni-ions. This anomaly is explained by the formation…
We report comprehensive synchrotron x-ray scattering and magnetic susceptibility studies of the doped spin-Peierls materials Cu_{1-x}Zn_xGeO_3 and CuGe_{1-y}Si_yO_3. Temperature versus dopant concentration phase diagrams are mapped out for…
The fraction of the paramagnetic phase surviving at the impurity-induced antiferromagnetic order transition of the doped spin-Peierls magnet Cu(1-x)Mg(x)GeO3 (x < 5%) is found to increase with an external magnetic field. This effect is…
The spin-Peierls transition is modeled in the dimer phase of the spin-$1/2$ chain with exchanges $J_1$, $J_2 = \alpha J_1$ between first and second neighbors. The degenerate ground state generates an energy cusp that qualitatively changes…
We have performed Electron Spin Resonance measurements on single crystals of the doped spin-Peierls compounds CuGe$_{1-y}$Si$_y$O$_3$ and Cu$_{1-x}$M$_x$GeO$_3$ with M = Zn, Mg, Ni ($x, y\leq 0.1$). The first part of our experiments was…
We have studied magnetic excitations in the dimerized spin-Peierls phase of CuGeO3, by high resolution inelastic neutron scattering. We measured the well-defined spin triplet dispersive mode which is gapped throughout the whole Brillouin…
ESR of the pure monocrystals of CuGeO3 is studied in the frequency range 9-75 GHz and in the temperature interval 1.2-25 K. The splitting of the ESR line into several spectral components is observed below 5 K, in the temperature range where…
Muon spin relaxation ($\mu$SR) measurements in high transverse magnetic fields ($\parallel \hat c$) revealed strong field-induced quasi-static magnetism in the underdoped and Eu doped (La,Sr)$_{2}$CuO$_{4}$ and…
A magnetic model is proposed for describing the incommensurate I phase of spin-Peierls systems. Based on the harmonicity of the lattice distortion, its main ingredient is that the distortion of the lattice adjusts to the average…
Spin correlations in the overdoped region of Bi1.75Pb0.35Sr1.90CuO6+z have been explored with Fe-doped single crystals characterized by neutron scattering, muon-spin-rotation (muSR) spectroscopy, and magnetic susceptibility measurements.…
We present experimental data for the Raman intensity in the spin-Peierls compound CuGeO_3 and theoretical calculations from a one-dimensional frustrated spin model. The theory is based on (a) exact diagonalization and (b) a recently…
Transitions between the ground singlet state to the excited triplet state has been observed in CuGeO3 by means of submillimeter wave electron spin resonance. The strong absorption intensity shows the break down of the selection rule. The…
High-resolution neutron inelastic scattering experiments in applied magnetic fields have been performed on La$_{1.895}$Sr$_{0.105}$CuO$_{4}$ (LSCO). In zero field, the temperature dependence of the low-energy peak intensity at the…
It is shown that nonadiabatic fluctuations of the soliton lattice in the spin-Peierls system CuGeO_3 lead to an important reduction of the NMR line widths. These fluctuations are the zero-point motion of the massless phasonic excitations.…
Incommensurate (IC) charge-order (CO) and spin density wave (SDW) order in electron doped SrMn1-xWxO3-{\delta} (x= 0.08 to 0.1875) have been studied using neutron diffraction.The study highlights the drastic effect of electron doping on the…
The phase diagram of a model describing doped CuGeO$_3$ is derived. The model emphasizes the role of local moments released by the impurities and randomly distributed inside the gaped singlet background. The phase diagram is investigated by…
We report an observation of a commensurate-incommensurate phase transition in a Dzyaloshinskii-Moriya spiral magnet Ba_2CuGe_2O_7. The transition is induced by applying a magnetic field in the plane of spin rotation. In this experiment we…