相关论文: Spin Dynamics of the Magnetoresistive Pyrochlore T…

Well defined spin waves were observed when the spin dynamics of Tl2Mn2O7, the first pyrochlore compound found to exhibit colossal magnetoresistance, was measured [J.W.Lynn et al., Phys.Rev.Lett. 80,4582(1998)], in stark contrast with the…

We discuss magnetotransport in a low density electron gas coupled to spin fluctuations near and above a ferromagnetic transition. Provided the density is low enough ($n \lesssim 1/\xi^{3}(T)$, with $\xi(T)$ the ferromagnetic correlation…

We present a parametric study of the diffuse magnetic scattering at (1/2,1/2,1/2) positions in reciprocal space, ascribed to a frozen antiferromagnetic spin ice state in single crystalline Tb2Ti2O7. Our high-resolution neutron scattering…

We investigate the temperature dependence of the spin dynamics in the pyrochlore magnet Nd$_2$Zr$_2$O$_7$ by neutron scattering experiments. At low temperature, this material undergoes a transition towards an "all in - all out"…

Er2Ti2O7 is believed to be a realization of an XY antiferromagnet on a frustrated lattice of corner-sharing regular tetrahedra. It is presented as an example of the order-by-disorder mechanism in which fluctuations lift the degeneracy of…

Neutron scattering has been used to study the magnetic correlations and long wavelength spin dynamics of La1-xCaxMnO3 in the ferromagnetic regime (0<=x<1/2). For x=1/3 (Tc=250K) where the magnetoresistance effects are largest the system…

The insulating pyrochlore compound Nd2Sn2O7 has been shown to undergo a second order magnetic phase transition at Tc ~ 0.91 K to a noncoplanar all-in--all-out magnetic structure of the Nd3+ magnetic moments. An anomalously slow paramagnetic…

The magnetic order, spin dynamics, and crystal structure of the multiferroic Sr0.56Ba0.44MnO3 have been investigated using neutron and x-ray scattering. Ferroelectricity develops at TC=305 K with a polarization of 4.2 microC/cm2 associated…

Neutron inelastic scattering has been used to probe the spin dynamics of the quantum (S=1/2) ferromagnet on the pyrochlore lattice Lu2V2O7. Well-defined spin waves are observed at all energies and wavevectors, allowing us to determine the…

Recent elastic and inelastic neutron scattering studies of the highly frustrated pyrochlore antiferromagnet Tb2Ti2O7 have shown some very intriguing features that cannot be modeled by the local <111> classical Ising model, naively expected…

High resolution time-of-flight neutron scattering measurements on Tb2Ti2O7 reveal a rich low temperature phase diagram in the presence of a magnetic field applied along [110]. In zero field at T=0.4 K, terbium titanate is a highly…

Neutron scattering experiments on a polycrystalline sample of the frustrated pyrochlore magnet Tb2Ti2O7, which does not show any magnetic order down to 50 mK, have revealed that it shows condensation behavior below 0.4 K from a thermally…

The spin dynamics of geometrically frustrated pyrochlore antiferromagnets Y2Mo2O7 and Tb2Mo2O7 have been investigated using muon spin relaxation. A dramatic slowing down of the moment fluctuations occurs as one approaches the spin freezing…

The pyrochlore antiferromagnet Tb2Ti2O7 has proven to be an enigma to experimentalists and theorists working on frustrated magnetic systems. The experimentally determined energy level structure suggests a local <111> Ising antiferromagnet…

In the pyrochlore compounds, Tb$_2$Ti$_2$O$_7$ and Tb$_2$Sn$_2$O$_7$, only the Tb$^{3+}$ ions are magnetic. They exhibit quite abnormal -- and, in view of their chemical similarity, strikingly different -- magnetic behaviour, as probed by…

Neutron scattering has been used to study the structure and spin dynamics of La$_{0.85}$Sr$_{0.15}$MnO$_3$. The magnetic structure of this system is ferromagnetic below T_C = 235 K. We see anomalies in the Bragg peak intensities and new…

By means of neutron scattering techniques we have investigated the frustrated pyrochlore magnet Ho_2Sn_2O_7, which was found to show a ferromagnetic spin-ice behavior below T \simeq 1.4 K by susceptibility measurements. High-resolution…

We report neutron scattering studies of the spin correlations of the geometrically frustrated pyrochlore Tb2Mo2O7 using single crystal samples. This material undergoes a spin-freezing transition below Tg~24 K, similar to Y2Mo2O7, and has…

Neutron scattering and magnetization measurements have been performed on the stuffed pyrochlore system Tb2+xTi2-2xNbxO7. We find that despite the introduction of chemical disorder and increasingly antiferromagnetic interactions, a spin…

Spin correlations in the pyrochlore antiferromagnet Y_2Ru_2O_7 with Curie-Weiss temperature $\Theta_{CW}=-1100$ K and critical temperature T_N=77 K were examined through neutron scattering. For $T_N<T<\Theta_{CW}/3$ the data show spin…