Long-Range Spin-Selective Transport in Chiral Metal–Organic Crystals with Temperature-Activated Magnetization
Amit Kumar Mondal, Noam Brown, Suryakant Mishra, Pandeeswar Makam, Dahvyd Wing, Sharon Gilead, Yarden Wiesenfeld, Gregory Leitus, Linda J. W. Shimon, Raanan Carmieli, David Ehre, G. Kamieniarz, Jonas Fransson, Oded Hod, Leeor Kronik, Ehud Gazit, Ron Naaman
Abstract
Room-temperature, long-range (300 nm), chirality-induced spin-selective electron conduction is found in chiral metal-organic Cu(II) phenylalanine crystals, using magnetic conductive-probe atomic force microscopy. These crystals are found to be also weakly ferromagnetic and ferroelectric. Notably, the observed ferromagnetism is thermally activated, so that the crystals are antiferromagnetic at low temperatures and become ferromagnetic above ∼50 K. Electron paramagnetic resonance measurements and density functional theory calculations suggest that these unusual magnetic properties result from indirect exchange interaction of the Cu(II) ions through the chiral lattice.