Hydrostatic pressure induced transformation of magnetism in a trimetallic CuMnFe Prussian blue analogue

Abstract

With chemical co-precipitation, trimetal Prussian blue analogue Cu0.71Mn0.79[Fe(CN)6]·7.3H2O was obtained. We used supercritical carbon dioxide extraction apparatus to pressurize the samples for 10 MPa, 20 MPa, and 42 MPa for 5 h. X-ray powder diffraction data show the single-phase of the sample at different pressures with a NaCl-type face-centered cubic structure. Trimetal Prussian blue analogs Cu0.71Mn0.79[Fe(CN)6]·7.3H2O include both ferromagnetic and antiferromagnetic exchange interactions among different metal ions and exhibit novel mixed magnetic property. Hydrostatic pressure may be a powerful tool for development of new functional magnets. Spontaneous magnetization in the field cooled (FC) magnetization above 10 MPa approaches a value three times larger than that at 1 atm, and the zero field cooled (ZFC) magnetization is also extremely sensitive to pressure. The results show that pressure can simultaneously enhance the ferromagnetic and antiferromagnetic interactions in this material. The Weiss constant decreases gradually with pressure increasing from 10 to 42 MPa, due to pressure-induced electron transfer from Mn2+/Cu2+ to Fe3+.