Related papers: Ordering and Spin Waves in NaNiO2 : A Stacked Quan…
Na$_x$CoO$_2$, the parent compound of the recently synthesized superconductor Na$_x$CoO$_2$:$y$H$_2$O, exhibits bulk antiferromagnetic order below $\sim20$ K for 0.75 $\leq x \leq$ 0.9. We have performed neutron scattering experiments in…
We report polarized and unpolarized neutron scattering measurements of the magnetic order in single crystals of Na0.5CoO2. Our data indicate that below T_N=88 K the spins form a novel antiferromagnetic pattern within the CoO2 planes,…
The quasi-one-dimensional helimagnet LiCu2O2 was studied by single crystal inelastic neutron scattering. The dispersion relation of spin wave excitations was measured in the vicinity of the principal magnetic Bragg reflection. A spin wave…
A novel metallic and magnetic transition metal oxide Ag2NiO2 is studied by means of resistivity, magnetic susceptibility, specific heat and X-ray diffraction. The crystal structure is characterized by alternating stacking of a Ni3+O2 layer…
We present a single crystal neutron scattering study of BaMn2Bi2, a recently synthesized material with the same ThCr2Si2-type structure found in several Fe-based unconventional superconducting materials. We show long range magnetic order,…
Elastic and inelastic neutron scattering were used to study the ordered phase of the quasi-one-dimensional spin-1/2 antiferromagnet ${\rm BaCu_{2}Si_{2}O_{7}}$. The previously proposed model for the low-temperature magnetic structure was…
We report inelastic neutron scattering measurements of the spin dynamics in the layered hexagonal magnet 2H-AgNiO2 which has stacked triangular layers of antiferromagnetically-coupled Ni2+ spins (S=1) ordered in a collinear alternating…
We present neutron scattering spectra taken from a single crystal of Na0.75CoO2, the precursor to a novel cobalt-oxide superconductor. The data contain a prominent inelastic signal at low energies (~10 meV), which is localized in wavevector…
Susceptibility, high-field magnetization and submillimeter wave electron spin resonance measurements of layered quasi-stoichiometric Li1-xNi1+xO2 are reported and compared to isomorphic NaNiO2. A new mechanism of magnetic frustration…
In the metallic magnet NbFe2, the low temperature threshold of ferromagnetism can be investigated by varying the Fe concentration within a narrow homogeneity range. NbFe2 is one of a number of compounds where modulated order is found to…
Large spin systems can exhibit unconventional types of magnetic ordering different from the ferromagnetic or N\'eel-like antiferromagnetic order commonly found in spin 1/2 systems. Spin-nematic phases, for instance, do not break…
Discovery of new states of matter is a key objective in modern condensed matter physics, which often leads to revolutionary technological advancements such as superconductivity. Quantum spin nematic, a ``hidden order'' that evades…
Spin waves are the low-energy excitations of magnetically ordered materials. They are key elements in the stability analysis of the ordered phase and have a wealth of technological applications. Recently, we showed that spin waves of a…
Strongly correlated ground states and exotic quasiparticle excitations in low-dimensional systems are central research topics in the solid state research community. The present work develops a new layered material and explores the physical…
In NaNiO2, Ni3+ ions form a quasi two dimensional triangular lattice of S = 1=2 spins. The magnetic order observed below 20K has been described as an A type antiferromagnet with ferro- magnetic layers weakly coupled antiferromagnetically.…
We report an inelastic neutron scattering study of magnetic excitations in a quantum paramagnet driven into a magnetically ordered state by chemical substitution, namely Ni(Cl$_{1-x}$Br$_x$)$_2$$\cdot$4SC(NH$_2$)$_2$ with $x=0.21(2)$. The…
Inelastic neutron scattering is used to investigate the collective magnetic excitations of the high-temperature superconductor parent antiferromagnet La2CuO4. We find that while the lower energy excitations are well described by spin-wave…
Continuum of spin excitations observed in inelastic neutron scattering experiments are often considered as a strong evidence of quantum spin liquid formation. When quantum spin liquid is indeed the ground state of a disorder-free magnetic…
Recent neutron scattering measurements reveal spin and charge ordering in the half-doped nickelate, La$_{3/2}$ Sr$_{1/2}$ NiO$_4$. Many of the features of the magnetic excitations have been explained in terms of the spin waves of diagonal…
Polarized neutron scattering experiments were performed on mixed compound CeRh0.6Co0.4In5 to clarify the nature of the low-temperature ordered states. Three nonequivalent Bragg peaks, characterized by the wave vectors of q_h ~…