title: Strain-Induced Spin Crossover in Phthalocyanine-Based Organometallic Sheets.
abstract: Motivated by the recent success in synthesizing two-dimensional Fe-phthalocyanine (poly-FePc) porous sheets, we studied strain-induced spin crossover in poly-TMPc (TM = Mn, Fe, Co, and Ni) systems by using first-principle calculations based on density functional theory. A small amount of biaxial tensile strain is found to not only significantly enhance the magnetic moment of the central TM atoms by 2 μB when the strain reaches a critical value, but also the systems undergo low-spin (LS) to high-spin (HS) transition. These systems, however, show different response to strain, namely, poly-FePc sheet becomes ferromagnetic (FM) while poly-MnPc and poly-NiPc sheets become antiferromagnetic (AFM). Poly-CoPc, on the other hand, remains AFM. These predicted results can be observed in suspended poly-TMPc sheets by using scanning tunneling microscope (STM) tips to manipulate strain.
authors: †Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
authors: Jian
authors: J
authors: Zhou
authors: ‡Center for Applied Physics and Technology, Peking University, Beijing 100871, China.
authors: Qian
authors: Q
authors: Wang
authors: †Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.|§Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, United States.
authors: Qiang
authors: Q
authors: Sun
authors: ∥Institute for Material Research, Tohoku University, Sendai, 980-8577, Japan.
authors: Yoshiyuki
authors: Y
authors: Kawazoe
authors: §Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, United States.
authors: Puru
authors: P
authors: Jena
keywords: biaxial tensile strain; crystal field effect; density functional theory; magnetic memory device; single atomic porous sheet