Studies of a Large Odd‐Numbered Odd‐Electron Metal Ring: Inelastic Neutron Scattering and Muon Spin Relaxation Spectroscopy of Cr8Mn
نویسندگان
چکیده
The spin dynamics of Cr8 Mn, a nine-membered antiferromagnetic (AF) molecular nanomagnet, are investigated. Cr8 Mn is a rare example of a large odd-membered AF ring, and has an odd-number of 3d-electrons present. Odd-membered AF rings are unusual and of interest due to the presence of competing exchange interactions that result in frustrated-spin ground states. The chemical synthesis and structures of two Cr8 Mn variants that differ only in their crystal packing are reported. Evidence of spin frustration is investigated by inelastic neutron scattering (INS) and muon spin relaxation spectroscopy (μSR). From INS studies we accurately determine an appropriate microscopic spin Hamiltonian and we show that μSR is sensitive to the ground-spin-state crossing from S=1/2 to S=3/2 in Cr8 Mn. The estimated width of the muon asymmetry resonance is consistent with the presence of an avoided crossing. The investigation of the internal spin structure of the ground state, through the analysis of spin-pair correlations and scalar-spin chirality, shows a non-collinear spin structure that fluctuates between non-planar states of opposite chiralities.
منابع مشابه
[CrF(O2CtBu)2]9: Synthesis and Characterization of a Regular Homometallic Ring with an Odd Number of Metal Centers and Electrons
The first regular homometallic ring containing an odd number of metal centers is reported. The ring was synthesized by means of amine-templated self-assembly. Extensive physical characterization studies, including magnetic measurements, powder inelastic neutron scattering (INS), and DFT calculations, show that the molecule has a near perfect match to the expected behavior for a frustrated syste...
متن کاملA classification of spin frustration in molecular magnets from a physical study of large odd-numbered-metal, odd electron rings.
The term "frustration" in the context of magnetism was originally used by P. W. Anderson and quickly adopted for application to the description of spin glasses and later to very special lattice types, such as the kagomé. The original use of the term was to describe systems with competing antiferromagnetic interactions and is important in current condensed matter physics in areas such as the des...
متن کاملDirect observation of optical magnons in YBa2Cu3O6.2.
The unit cell of the high-Tc cuprate YBa2Cu3O61x contains pairs of closely spaced CuO2 layers, the bilayers, separated by CuO chains. Inelastic neutron scattering experiments have demonstrated that electronic states in different CuO2 layers belonging to one bilayer are strongly coupled at all doping levels, whereas the coupling across the chains is much weaker. The nature of this coupling is we...
متن کاملReduction of ordered moment and Néel temperature of quasi one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3
We report elastic neutron diffraction and muon spin relaxation (μSR) measurements of the quasi one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3, which have extraordinarily reduced TN/J ratios. We observe almost resolution-limited antiferromagnetic Bragg reflections in Sr2CuO3 and obtain a reduced ordered moment size of ∼0.06μB. We find that the ratio of ordered moment size μ(Ca2CuO3)/μ(Sr2C...
متن کاملMagnetic Raman optical activity and Raman electron paramagnetic resonance
All molecules in a magnetic field parallel to the incident light beam show a small difference in the intensity of Raman scattering at 900 in right and left circularly polarized incident light. The most interesting effects occur in vibrational resonance Raman scattering from odd—electron transition metal halides, and in pure electronic resonance Raman scattering from both odd— and even—electron ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 22 شماره
صفحات -
تاریخ انتشار 2016