ترغب بنشر مسار تعليمي؟ اضغط هنا

High-field moment polarization in the itinerant ferromagnet URhSi

234   0   0.0 ( 0 )
 نشر من قبل William Knafo
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

We report a high-magnetic-field study of the itinerant ferromagnet URhSi. Magnetization and electrical resistivity were measured under magnetic fields $mu_0H$ up to 58~T applied along the directions $mathbf{a}$, $mathbf{b}$, and $mathbf{c}$ of the orthorhombic structure and temperatures $T$ ranging from 1.5 to 50 K. For $mathbf{H}parallelmathbf{b}$, pseudo-metamagnetism at $mu_0H_msimeq30-40$~T is associated with a broad step in the magnetization and a maximum in the resistivity. The properties of URhSi are discussed and compared with those of the isostructural superconducting ferromagnets URhGe and UCoGe and of the superconducting paramagnet UTe$_2$.



قيم البحث

اقرأ أيضاً

276 - W. Knafo , T.D. Matsuda , D. Aoki 2012
We report magnetization and magnetoresistivity measurements on the isostructural ferromagnetic superconductors UCoGe and URhGe in magnetic fields up to 60 T and temperatures from 1.5 to 80 K. At low-temperature, a moment polarization in UCoGe in a fi eld $mu_0mathbf{H}parallelmathbf{b}$ of around 50 T leads to well-defined anomalies in both magnetization and magnetoresistivity. These anomalies vanish in temperatures higher than 30-40 K, where maxima in the magnetic susceptibility and the field-induced variation of the magnetoresistivity are found. A comparison is made between UCoGe and URhGe, where a moment reorientation in a magnetic field $mu_0mathbf{H}parallelmathbf{b}$ of 12 T leads to field-induced reentrant superconductivity.
The physics of weak itinerant ferromagnets is challenging due to their small magnetic moments and the ambiguous role of local interactions governing their electronic properties, many of which violate Fermi liquid theory. While magnetic fluctuations p lay an important role in the materials unusual electronic states, the nature of these fluctuations and the paradigms through which they arise remain debated. Here we use inelastic neutron scattering to study magnetic fluctuations in the canonical weak itinerant ferromagnet MnSi. Data reveal that short-wavelength magnons continue to propagate until a mode crossing predicted for strongly interacting quasiparticles is reached, and the local susceptibility peaks at a coherence energy predicted for a correlated Hund metal by first-principles many-body theory. Scattering between electrons and orbital and spin fluctuations in MnSi can be understood at the local level to generate non-Fermi liquid character. These results provide crucial insight into the role of interorbital Hunds exchange within the broader class of enigmatic multiband itinerant, weak ferromagnets.
Different from previous scenarios that topological magnons emerge in local spin models, we propose an alternative that itinerant electron magnets can host topological magnons. A one-dimensional Tasaki model with a flat band is considered as the proto type. This model can be viewed as a quarter filled periodic Anderson model with impurities located in between and hybridizing with the nearest-neighbor conducting electrons, together with a Hubbard repulsion for these electrons. By increasing the Hubbard interaction, the gap between the acoustic and optical magnons closes and reopens while the Berry phase of the acoustic band changes from 0 to $pi$, leading to the occurrence of a topological transition. After this transition, there always exist in-gap edge magnonic modes which is consistent with the bulk-edge correspondence. The Hubbard interaction driven transition reveals a new mechanism to realize non-trivial magnon bands.
LaCrGe$_3$ is an itinerant ferromagnet with a Curie temperature of $T_{rm c}$ = 85 K and exhibits an avoided ferromagnetic quantum critical point under pressure through a modulated antiferromagnetic phase as well as tri-critical wing structure in its temperature-pressure-magnetic field ($T$-$p$-$H$) phase diagram. In order to understand the static and dynamical magnetic properties of LaCrGe$_3$, we carried out $^{139}$La nuclear magnetic resonance (NMR) measurements. Based on the analysis of NMR data, using the self-consistent-renomalization (SCR) theory, the spin fluctuations in the paramagnetic state are revealed to be isotropic ferromagnetic and three dimensional (3D) in nature. Moreover, the system is found to follow the generalized Rhodes-Wohfarth relation which is expected in 3D itinerant ferromagnetic systems. As compared to other similar itinerant ferromagnets, the Cr 3$d$ electrons and their spin fluctuations are characterized to have a relatively high degree of localization in real space.
We have performed an extensive pressure-dependent structural, spectroscopic, and electrical transport study of LaCrSb$_3$. The ferromagnetic phase (T$_C$ = 120 K at p = 0 GPa) is fully suppressed by p = 26.5 GPa and the Cr-moment decreases steadily w ith increasing pressure. The unit cell volume decreases smoothly up to p = 55 GPa. We find that the bulk modulus and suppression of the magnetism are in good agreement with theoretical predictions, but the Cr-moment decreases smoothly with pressure, in contrast to steplike drops predicted by theory. The ferromagnetic ordering temperature appears to be driven by the Cr-moment.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا