Magnetic Resonances in Perovskite-Type Layer Structures

In addition to our recent investigations of Rb
2
MnCl
4
, and (CH
3
NH
3
)
2
MnCl
4
, we have studied the antiferromagnetic resonance of similar manganese compounds with longer hydrocarbon chains, namely (C
n
H
2n+1
NH
3
)
2
MnCl
4
with n = 2,3 and NH
3
(CH
2
)
m
NH
3
MnCl
4
with m = 2,4,5. Our essential result from these magnetic resonance measurements in the millimeter wave range is that the zero field antiferromagnetic resonance frequency decreases drastically for increasing chain lengths, i.e. for increasing separation of the magnetic layers in these compounds.