@article{886c70a2a9694064ad2657a6081f4045,
title = "Sound propagation near the tricritical point of FeCl2",
abstract = "The magnetically induced phase transitions, near the tricritical point of FeCl2 were studied by acoustic velocity measurements. Longitudinal waves propagating along the (100) trigonal axis exhibit a critical shift in the velocity along the second order λ-line and anomalous change at the first order phase transitions. The phase diagram in the plane of temperature and applied magnetic field is constructed near the tricritical point.",
author = "G. Gorodetsky and A. Shaulov and V. Volterra and J. Makovsky",
note = "Funding Information: THE COUPLING of sound waves to critical fluctuations near phase transitions, gives rise to a pronounced attenuation and velocity shift \[1\].These phenomena have phase transitions. Here we report on the observation of a critical softening of the elastic stiffness near the tricitical point of a metamagnetic FeC! 2 \[2—9\]F.eC12 is an antiferromagnet with a layered type spin structure. Thereisa2~feiorrnosma,nadgnaenticaenxticfhearrnogmeaJ1gnbeettiwceeexnchtahnege. ~2 planebetweenFeadjacent planes, that is about twenty times weaker than .11. The magnetic moments are aligned by a relatively high anisotropy perpendicular to the Fe2~ layers and along the trigonal axis of the crystal. It has been found that below the tricritical temperature —21 K under an increasing applied magnetic field ~ the crystal undergoes a first order transition to a paramagnetic state. The transition is at constant internal field and over a range of~ and during the transition the crystal is a mixture of para-and antiferromagnetic domains. Above T~the transition from the antiferromagnetic phase to the paramagnetic phase is of second-order type. The magnetic phase diagram of FeCl 2 has been * This work was supported in part by the U.S.—Israel Binational Science Foundation through Research Grant No. 452. t Present address: Center for Materials Science and Engineering Massachusetts Institute of Technology, Cambridge.",
year = "1978",
month = jan,
day = "1",
doi = "10.1016/0038-1098(78)90924-9",
language = "English",
volume = "25",
pages = "1129--1131",
journal = "Solid State Communications",
issn = "0038-1098",
publisher = "Elsevier Ltd.",
number = "12",
}