Electron Spin Decoherence Dynamics in Magnetic Manganese Hybrid Organic–Inorganic Crystals: The Effect of Lattice Dimensionality

Abstract

Organic−inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead-and tinbased hybrids, these systems generally show short spin decoherence lifetimes, and their correlation with the lattice framework is still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine) 2 MnCl 4 , ((R)-3-fluoropyrrolidinium)MnCl 3 , and (pyrrolidinium) 2 MnCl 4 , which represent a change in lattice dimensionality from 2D and 1D to 0D, and studied their spin decoherence processes using continuous-wave electron spin resonance spectroscopy. All manganese hybrids exhibit nanosecond-scale spin decoherence time τ 2 dominated by the symmetry-directed spin exchange interaction strengths of Mn 2+ −Mn 2+ pairs, which is much longer than lead-and tin-based metal hybrids. In contrast to the similar temperature variation laws of τ 2 in 2D and 0D structures, which first increase and gradually drop afterward, the 1D structure presents a monotonous rise of τ 2 with the temperatures, indicating the strong correlation of spin decoherence with the lattice rigidity of the inorganic framework. This is also rationalized on the basis that the spin decoherence is governed by the competitive contributions from motional narrowing (prolonging the τ 2 ) and electron−phonon coupling interaction (shortening the τ 2 ), both of which are thermally activated, with the difference that the former is more pronounced in rigid crystalline lattices.

Circularly Polarized Luminescence Induced by Hydrogen‐Bonding Networks in a One‐Dimensional Hybrid Manganese(II) Chloride

“…In addition, we measured these crystals’ magnetic hysteresis loops with a vibrating sample magnetometer (VSM) at 298 K as shown in Figure 3f. It is found that the hysteresis loops of R ‐1 and R ‐2 are almost straight lines, indicating the paramagnetic properties and absence of Mn−Mn coupling for these samples [49–50] . All results imply that the strong red emission is caused by the d–d ( 4 T 1 → 6 A 1 ) transition of Mn 2+ , consistent with previously reported D / L ‐(tert‐butyl prolinate)MnCl 3 and (tetramethylammonium chloride)MnCl 3 1D Mn‐based halides [29,51] …”

Ferroics in Hybrid Organic–Inorganic Perovskites: Fundamentals, Design Strategies, and Implementation

“…The substitution of B 2+ ‐site metal ions with light transition metal elements is another way to prolong the spin relaxation lifetime. Zheng and co‐workers observed nanosecond‐scale spin relaxation lifetimes in magnetic manganese hybrids at the room‐temperature regime that exhibit a strong correlation with the lattice dimensionality of the inorganic frame; [ 134 ] in addition, these spin relaxation lifetimes are much longer than lead‐ and tin‐based HOIPs. [ 146,147 ] Transition metal‐based HOIPs also facilitate the concurrent presence of ferroelectric and magnetic orders supported by antisymmetric D–M interaction, affording the possibility for the electric manipulation of spin‐polarized currents.…”

Magnetic hybrid transition metal halides

“…Zheng et al systematically studied a series of manganese halides of 2D (4-fluorobenzylamine) 2 MnCl 4 , 1D (( R )-3-fluoropyrrolidinium)MnCl 3 , and 0D (pyrrolidinium) 2 MnCl 4 and demonstrated the effect of structure dimensions on spin decoherence processes. 90 The spin decoherence time follows the trend 2D > 1D > 0D due to the reduced connectivity and larger distance between adjacent Mn 2+ –Mn 2+ ions in lower structure dimensions. It indicates that the structure dimensions can strongly affect the magnetic interaction.…”