Multifunctional Ni(II)-Based Metamagnetic Coordination Polymers for Electronic Device Fabrication

Area of Science:

• Coordination Chemistry
• Materials Science
• Solid-State Physics

Background:

• Schiff base ligands are versatile building blocks for coordination polymers.
• Coordination polymers with specific metal ions can exhibit interesting electronic and magnetic properties.

Purpose of the Study:

• To synthesize and characterize novel one-dimensional thiocyanato-bridged nickel(II) coordination polymers.
• To investigate the electrical conductivity and photoresponsive behavior of these materials.
• To explore their potential as semiconductor devices and analyze their magnetic properties.

Main Methods:

• Synthesis of coordination polymers using 8-aminoquinoline-based Schiff base ligands, Ni(II), and thiocyanate.
• Characterization of crystal structure and conductivity measurements.
• Fabrication and testing of metal-semiconductor junction devices under varying light conditions.
• Magnetic measurements including isothermal magnetization and DC/AC susceptibility.

Main Results:

• Two isostructural one-dimensional coordination polymers, [Ni(L1)(NCS)2] and [Ni(L2)(NCS)2], were synthesized.
• Both compounds demonstrated semiconductor behavior, with conductivity increasing under photoillumination.
• Thin film devices exhibited Schottky diode characteristics, with improved rectification ratios under irradiation.
• Magnetic studies revealed ferromagnetic intrachain and antiferromagnetic interchain interactions, with metamagnetic behavior observed at low temperatures.

Conclusions:

• The synthesized nickel(II) coordination polymers show promising semiconductor and diode properties, particularly compound 2.
• These materials are suitable candidates for applications in electrochemical devices.
• The compounds exhibit complex magnetic behaviors, including metamagnetism and long-range ferromagnetic order.