What did scientists discover?
Compounds containing the rare-earth element cerium exhibit a wide variety of fascinating and only partially understood behaviors. This work characterizes the phase diagram of the novel compound Ce3TiSb5, which exhibits an unusual inverse melting of magnetic order: that is, on cooling at 1.8K (gold arrow) the material becomes magnetic (green phase) then loses that magnetic order upon further cooling, which is a very unusual phenomenon.
THE TOOLS THEY USED
This research was conducted in the the MagLab's High B/T Facility on a fast-turnaround instrument that provided a low electromagnetic noise, low temperature (down to 50 mK), and high magnetic field (up to 10 Tesla) environment.
Why is this important?
The freezing of water into ice upon cooling is a familiar phenomenon. However, under certain unusual circumstances, a liquid can melt upon cooling. This somewhat counterintuitive phenomenon is known as inverse melting, and it is known to occur in a variety of different systems including polymers, proteins, and liquid crystals. It has been proposed that inverse melting can be observed in magnetic systems. This work identifies Ce3TiSb5 as a metallic magnet in which inverse melting does occur: an ordered arrangement of the magnetic moments can become disordered (i.e. "melt") upon cooling.
Who did the research?
The work involved a wonderfully diverse group of four early career scientists (two undergraduates and two graduate students, including one REU student) -
D.E. Jackson1, T. Stevenson1, B. Jones1, D. VanGennep1, J.S. Xia1,2, R.E. Baumbach2,3, J.J. Hamlin1,2
1University of Florida; 2National MagLab; 3Florida State University
Why did they need the MagLab?
This research required the unique combination of magnetic field, low temperature, and low-noise environment available in the High B/T Facility.
G.S. Boebinger (NSF DMR-1157490, NSF DMR-1644779); J.J. Hamlin (DMR-1453752); S. Hershfield (DMR-1156737, REU for T. Stevenson)
For more information, contact Mark Meisel.