The luminescence spectrum of {DyCs} (4) compound under a pulsed magnetic field up to 36T at 5K.
(Chem. Sci. 7, 5020-5031 (2016))
Background
Single-molecule magnets (SMMs) have potential applications in high-density information storage, molecular spintronics and quantum computing. One of the important factors affecting Ln-SMM behavior on surfaces is that the splitting of the magnetic sublevels of 4f-electrons by the ligand field is sensitive to the coordination environment, which would change dramatically before and after transfer onto the substrates. To investigate the behavior of individual molecules on surfaces, energies of the magnetic sublevels for the ground term are required. Magneto-optical PL measurement is a powerful way to investigate such energy levels.
What we discover?
The photoluminescence spectra offer verification of the energy gap between the two lowest sublevels of the ground term, and show that the pathway of the thermal magnetic relaxation process is the first excited states involved for compounds 1-4 and 8. The luminescence spectra at low temperature discriminate the small difference in energies for the magnetic sublevels of Dy ions in compound 8. The average g value is deduced from the luminescence spectra and analyzed using a reduced Zeeman model, while the information about the Zeeman splitting on Kramers doublets of the ground term 6H15/2 of Dy(III), which may be difficult to be obtained by normal EPR measurements, is obtained by using magneto-optical PL measurements under high magnetic field.
Why is this important?
The luminescence spectroscopy measurement under a strong magnetic field is thought to a new and complementary method to study the lowest magnetic sublevels and give insightful information on SMMs. These SMMs will be also attractive multifunctional materials in the application of molecular spintronics and quantum computing.
Why did they need WHMFC?
The luminescence spectra under varying external magnetic fields present the positions of the sublevels of the ground term, which may be difficult to be obtainviathe electron paramagnetic resonance technology, since the large ligand field splitting of Ln ions challenges the faculties of EPR in high frequency and high magnetic field.
Who did the research?
Ye Bi1,Cheng Chen2,Yi-Fang Zhao1,Yi-Quan Zhang3,Shang-Da Jiang1,Bing-Wu Wang1,Jun-Bo Han2,Jun-Liang Sun1,Zu-Qiang Bian1,Zhe-Ming Wang1and Song Gao1
1Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
2Wuhan National High Magnetic Center, Huazhong University of Science and Technology, Wuhan 430074, China
3Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China
