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Magneto‐optical investigations of the two‐dimensional ferromagnet (CH 3 NH 3 ) 2 CuCl 4
Author(s) -
Arend H.,
Schoenes J.,
Wachter P.
Publication year - 1975
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220690112
Subject(s) - faraday effect , condensed matter physics , magnetization , magnetic circular dichroism , absorption edge , magnetic susceptibility , magnetic field , ferromagnetism , field (mathematics) , faraday rotator , chemistry , absorption spectroscopy , materials science , physics , optics , spectral line , mathematics , quantum mechanics , astronomy , band gap , pure mathematics
The optical absorption of (CH 3 NH 3 ) 2 CuCl 4 has been investigated at 300 K in the spectral range between 0.2 and 40 μm and down to 4.2 K between the optical absorption edge and 2.5 μm. Absorption has also been measured with polarized light, parallel or perpendicular to the crystal axes or a magnetic field. In addition the magnetic linear dichroism and the Faraday rotation has been investigated in function of frequency, magnetic field strength and temperature, as well above as below T C = 8.9 K. From the Faraday rotation one can evaluate the magnetization for T < T C and the susceptibility for T > T C . The discussion is made in terms of critical exponents of the susceptibility. A cross‐over region could be determined above, but close to T C . The system changes from three dimensionality to two dimensional Ising. At higher temperatures only molecular field behavior is observed.