Magnetic Excitation Spectrum of Rouaite, Cu₂(NO₃)(OD)₃

The mineral rouaite, Cu₂(NO₃)(OD)₃ in synthetic form, consists of triangular-lattice planes of Cu2+, compressed along the crystallographic b axis to form chains. Below 4.8 K, these chains alternate ferro- and antiferromagnetic, with consecutive ferromagnetic chains having opposite spin orientation. This is essentially the same magnetic sublattice and magnetic ground state as in Cu(OD)₃Br (botallackite), the only material in which spinon-magnon mixing has been reported to date. We propose to look for spinon-magnon mixing in rouaite, starting with time-of-flight spectroscopy. This will also reveal the magnon spectrum, allowing us to model the interaction parameters underlying the magnetic order. Above 4.8 K, rouaite enters an incommensurate phase, the excitation spectrum of which would also provide crucial information.

合成态的鲁阿特矿（rouaite，化学式为Cu₂(NO₃)(OD)₃）由二价铜离子（Cu²+）构成的三角晶格平面组成，该结构沿晶体学b轴被压缩形成链状结构。在4.8开尔文以下时，这些链呈现铁磁与反铁磁交替排布的特征，且相邻铁磁链的自旋取向相反。其磁子晶格与磁基态与化学式为Cu(OD)₃Br的鲍拉契克矿（botallackite）基本一致，而后者是迄今为止唯一被报道存在自旋子-磁振子混合（spinon-magnon mixing）现象的材料。我们提议对鲁阿特矿中的自旋子-磁振子混合现象展开研究，首选手段为飞行时间光谱法，该方法可同时获取磁振子能谱，进而能够对磁有序背后的相互作用参数进行建模。在4.8开尔文以上时，鲁阿特矿会进入非公度相，该相的激发能谱也将为相关研究提供关键信息。