Field induced low-spin high-spin transition

Abstract

We have investigated the temperature and magnetic field induced high-spin low-spin transition of [ μ-Tris(1,4-bis(tetrazol-1-yl)butane- N4, N4′)iron(II)] Bis(hexafluorophosphate) in transient megagauss fields using optical reflection measurements at λ=0.632 and 0.541 μm radiation. The experimental setup uses plastic optical fiber (POF) in an environment between 140 and 200 K. For sample temperature within this transition range magnetic field induced small reflection changes with strong hysteresis were detected. Evidently the strong (160 T) but short (5 μs) magnetic field pulse cannot drive the transition into saturation. Using magnetic field pulses with different time constants the dynamic process could be studied. For [ μ-Tris(1,4-bis(tetrazol-1-yl)butane- N4, N4′)iron(II)] Bis(hexafluorophosphate) it was found that the solvent used in the actual production process of the material had a strong influence on the experimental results.