Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userElectronic phase separation in the itinerant metamagnetic transition of Sr$_4$Ru$_3$O$_{10}$
109
0
0.0
(
0
)
Authors
Zhiqiang Mao
Ask ChatGPT about the research
No Arabic abstract
Triple-layered ruthenate Sr$_4$Ru$_3$O$_{10}$ shows a first-order itinerant metamagnetic transition for in-plane magnetic fields. Our experiments revealed rather surprising behavior in the low-temperature transport properties near this transition. The in-plane magnetoresistivity $rho$$_{ab}$(H) exhibits ultrasharp steps as the magnetic field sweeps down through the transition. Temperature sweeps of $rho$$_{ab}$ for fields within the transition regime show non-metallic behavior in the up-sweep cycle of magnetic field, but show a significant drop in the down-sweep cycle. These observations indicate that the transition occurs via a new electronic phase separation process; a lowly polarized state is mixed with a ferromagnetic state within the transition regime.
rate research
Read More
Sr$_4$Ru$_3$O$_{10}$, the $n$ = 3 member of the Ruddlesden-Popper type ruthenate Sr$_{n+1}$Ru$_n$O$_{3n+1}$, is known to exhibit a peculiar metamagnetic transition in an in-plane magnetic field. However, the nature of both the temperature- and field-dependent phase transitions remains as a topic of debate. Here, we have investigated the magnetic transitions of Sr$_4$Ru$_3$O$_{10}$ via single-crystal neutron diffraction measurements. At zero field, we find that the system undergoes a ferromagnetic transition with both in-plane and out-of-plane magnetic components at $T_{c}$ ~ 100 K. Below $T^{*}$ ~ 50 K, the magnetic moments incline continuously toward the out-of-plane direction. At $T$ ~ 1.5 K, where the spins are nearly aligned along the $c$ axis, a spin reorientation occurs above a critical field $B_c$, giving rise to a spin component perpendicular to the plane defined by the field direction and the $c$ axis. We suggest that both the temperature- and field-driven spin reorientations are associated with a change in the magnetocrystalline anisotropy, which is strongly coupled to the lattice degrees of freedom. This study elucidates the long-standing puzzles on the zero-field magnetic orders of Sr$_4$Ru$_3$O$_{10}$ and provides new insights into the nature of the field-induced metamagnetic transition.
We report, for the first time, measurements of the third order, $chi_3$ and fifth order, $chi_5$, susceptibilities in an itinerant oxide metamagnet, Sr$_3$Ru$_2$O$_7$ for magnetic fields both parallel and perpendicular to the c-axis. These susceptibilities exhibit maxima in their temperature dependence such that $T_1 approx 2T_3 approx 4T_5$ where the $T_i$ are the position in temperature where a peak in the $i$-th order susceptibility occurs. These features taken together with the scaling of the critical field with the temperature $T_1$ observed in a diverse variety of itinerant metamagnets find a natural explanation in a single band model with one Van Hove singularity (VHS) and onsite repulsion $U$. The separation of the VHS from the Fermi energy $Delta$, sets a single energy scale, which is the primary driver for the observed features of itinerant metamagnetism at low temperatures.
The solid solution between the ferromagnetic metal SrRuO$_3$ and the enhanced paramagnetic metal SrRhO$_3$ was recently reported [K. Yamaura et al., Phys. Rev. B 69 (2004) 024410], and an unexpected feature was found in the specific heat data at $x$=0.9 of SrRu$_{1-x}$Rh$_x$O$_3$. The feature was reinvestigated further by characterizing additional samples with various Ru concentrations in the vicinity of $x$=0.9. Specific heat and magnetic susceptibility data indicate that the feature reflects a peculiar magnetism of the doped perovskite, which appears only in the very narrow composition range 0.85$<$$x$$le$0.95.
We report a study of the magnetoresistivity of high purity Sr$_3$Ru$_2$O$_7$, in the vicinity of its electronic nematic phase. By employing a triple-axis (9/1/1T) vector magnet, we were able to precisely tune both the magnitude and direction of the in-plane component of the magnetic field (H$_parallel$). We report the dependence of the resistively determined anisotropy on H$_parallel$ in the phase, as well as across the wider temperature-field region. Our measurements reveal a high-temperature anisotropy which mimics the behaviour of fluctuations from the underlying quantum critical point, and suggest the existence of a more complicated phase diagram than previously reported.
Rare $d$-electron derived heavy-fermion properties of the solid-solution series LaCu$_3$Ru$_x$Ti$_{4-x}$O$_{12}$ were studied for $1 leq x leq 4$ by resistivity, susceptibility, specific-heat measurements, and magnetic-resonance techniques. The pure ruthenate ($x = 4$) is a heavy-fermion metal characterized by a resistivity proportional to $T^2$ at low temperatures $T$. The coherent Kondo lattice formed by the localized Ru 4$d$ electrons is screened by the conduction electrons leading to strongly enhanced effective electron masses. By increasing titanium substitution the Kondo lattice becomes diluted resulting in single-ion Kondo properties like in the paradigm $4f$-based heavy-fermion compound Ce$_x$La$_{1-x}$Cu$_{2.05}$Si$_2$ [M. Ocko {em et al.}, Phys. Rev. B textbf{64}, 195106 (2001)]. In LaCu$_3$Ru$_x$Ti$_{4-x}$O$_{12}$ the heavy-fermion behavior finally breaks down on crossing the metal-to-insulator transition close to $x = 2$.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
