6100 spectrometer

The chemical formulas of the samples were determined by elemental analyses. The ratios of the metals (Cs, K, Mn, and Fe) were obtained by inductively coupled plasma mass spectroscopy using Agilent 7700. The amounts of C, H, and N contained in the samples were determined by standard microanalytical methods. The chemical formula, K^I_aCs^I_bMn^II[Fe^II(CN)₆]_c[Fe^III(CN)₆]_d·zH₂O, was determined considering charge neutrality. Because the valences of K^I, Cs^I, Mn^II, [Fe^II(CN)₆], and [Fe^III(CN)₆] are +1, +1, +2, −4, and −3, respectively, a + b + 2 − 4c − 3d = 0 should be satisfied. For the far-infrared measurements, a JASCO 6100 spectrometer was used. XRD measurements were performed with a Rigaku Ultima IV diffractometer with a Cu K_α radiation (λ = 1.5418 Å). The PDXL program of Rigaku was used for Rietveld analyses.

SEM and TEM images were acquired using a JEOL JSM-7001F and JEOL JEM 2000EX, respectively. XRD patterns were measured by a Rigaku Ultima IV and Rigaku SmartLab. AFM and MFM measurements were conducted by a Hitachi High-Tech Science AFM5000II/AFM5300E MFM. For the Faraday effect and Far-IR measurements, a JASCO E-250 magneto-optical meter and a JASCO 6100 spectrometer were used, respectively. The magnetic measurements were carried out using a Quantum Design MPMS SQUID magnetometer. The impedance measurements were conducted with an Agilent 4294A precision impedance analyzer. Ferroelectric property was measured using a TF Analyzer 1000, aixACCT electric polarization hysteresis meter.