Effect of pressure on the magnetic properties of TM(3)[Cr(CN)(6)](2)·12H(2)O
M Zentková1, Z Arnold, J Kamarád
1Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 043 53 Košice, Slovakia.
Abstract:
We present the results of magnetization and AC susceptibility measurements performed on ferrimagnetic Mn(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O and ferromagnetic Ni(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O systems under pressures up to 0.9 GPa in a commercial SQUID magnetometer. The magnetization process is affected by pressure: magnetization saturates at higher magnetic field, saturated magnetization μ(s) of Ni(3)[Cr(CN)(6)](2) is reduced and almost unaffected for Mn(3)[Cr(CN)(6)](2) at low temperatures. The Curie temperature T(C) of Mn(3)[Cr(CN)(6)](2) increases with the applied pressure, ΔT(C)/Δp = 25.5 K GPa(-1), due to a strengthened super-exchange antiferromagnetic interaction J(AF), but it is not affected significantly in the case of Ni(3)[Cr(CN)(6)](2) with a dominant ferromagnetic J(F) super-exchange interaction. The increase in the J(AF) interaction is attributed to the enhanced value of the single electron overlapping integral S and the energy gap Δ of the mixed molecular orbitals t(2g) (Mn(2+)) and t(2g) (Cr(III)) induced by pressure.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Paramagnetism
Ferromagnetism
Magnetic Moment of an Electron
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...


