著者

Iio Katsunori Sakatani Mitsuo Nagata Kazukiyo

出版者

一般社団法人日本物理学会

雑誌

Journal of the Physical Society of Japan (ISSN:00319015)

巻号頁・発行日

vol.45, no.5, pp.1567-1574, 1978-11-15

被引用文献数

17

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By measuring optical birefringences the behaviour of short-range order has beenstudied on quadratic-layer quasi-Heisenberg antiferromagnets : K.NiF., Rb.NiF.,Ba.NiF, and K.CoF.. An explicit form of the spin-dependent birefringence forthese systems is given, which is proportional to the nearest-neighbouring cor-relation functions<.SjS l >. It is shown that with increasing Ising-like characterthe high tempet'ature persistence of<S7,5Z>is rc:duced. In the case of K2C0F.,where the Ising-like anisotropy is comparable to the isotropic exchange field,a symmetric and logarithmic anomaly in the behaviour of<,SjS,) has beenobserved for 17' -7Nl/7'N<7.5'l0 " afound the Neel point.

著者

Yamamoto Ikuo Iio Katsunori Nagata Kazukiyo

出版者

一般社団法人日本物理学会

雑誌

Journal of the Physical Society of Japan (ISSN:00319015)

巻号頁・発行日

vol.49, no.5, pp.1756-1759, 1980-11-15

被引用文献数

6

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Magnetic anisotropies of several mangane secryst,als have been naeasured accu-rately between 77 K and 300 K by using a high sensitive torque-naeter. ,As ispredicted by the high temperature expansion th<cory, the observed naagneticanisotropies vary as the inverse square of the tempe.rature. The crystal field split-ting parameters D and E have been obtained for<>ach pure magnetically densesanuple. In compounds having the octahedron witla two water molecules alongthe axial direction, the splitting parameters D have been found to be about -0.1cm-', which value is two tiznes or one order of mag;nitude larger than the typicalvalue of Mn" surrounded by a distorted octaheclron composed of six si.milarligands. Especially, the value 17)l =0.368 cm ' fo'ar [(CH.).NlI]MnBr.2I-[.0 isthe largest one reported to date.