TY - JOUR
T1 - Precise measurements of radio-frequency magnetic susceptibility in ferromagnetic and antiferromagnetic materials
AU - Vannette, M. D.
AU - Sefat, A. S.
AU - Jia, S.
AU - Law, S. A.
AU - Lapertot, G.
AU - Bud'ko, S. L.
AU - Canfield, P. C.
AU - Schmalian, J.
AU - Prozorov, R.
N1 - Funding Information:
Work at the Ames Laboratory was supported by the Department of Energy—Basic Energy Sciences under Contract No. DE-AC02-07CH11358. R.P. is grateful to his cat, Linux, for her purry support and acknowledges support from the NSF Grant no. DMR-06-03841 and the Alfred P. Sloan Foundation.
PY - 2008/2
Y1 - 2008/2
N2 - Dynamic magnetic susceptibility, χ, was studied in several intermetallic materials exhibiting ferromagnetic, antiferromagnetic and metamagnetic transitions. Precise measurements by using a 14 MHz tunnel diode oscillator (TDO) allow detailed insight into the field and temperature dependence of χ. In particular, local moment ferromagnets show a sharp peak in χ (T) near the Curie temperature, TC. The peak amplitude decreases and shifts to higher temperatures with very small applied dc fields. Anisotropic measurements of CeVSb3 show that this peak is present provided the magnetic easy axis is aligned with the excitation field. In a striking contrast, small moment, itinerant ferromagnets (i.e., ZrZn2) show a broad maximum in χ (T) that responds differently to applied field. We believe that TDO measurements provide a very sensitive way to distinguish between local and itinerant moment magnetic orders. Local moment antiferromagnets do not show a peak at the Néel temperature, TN, but only a sharp decrease of χ below TN due to the loss of spin-disorder scattering changing the penetration depth of the ac excitation field. Furthermore, we show that the TDO is capable of detecting changes in spin order as well as metamagnetic transitions. Finally, critical scaling of χ (T, H) in the vicinity of TC is discussed in CeVSb3 and CeAgSb2.
AB - Dynamic magnetic susceptibility, χ, was studied in several intermetallic materials exhibiting ferromagnetic, antiferromagnetic and metamagnetic transitions. Precise measurements by using a 14 MHz tunnel diode oscillator (TDO) allow detailed insight into the field and temperature dependence of χ. In particular, local moment ferromagnets show a sharp peak in χ (T) near the Curie temperature, TC. The peak amplitude decreases and shifts to higher temperatures with very small applied dc fields. Anisotropic measurements of CeVSb3 show that this peak is present provided the magnetic easy axis is aligned with the excitation field. In a striking contrast, small moment, itinerant ferromagnets (i.e., ZrZn2) show a broad maximum in χ (T) that responds differently to applied field. We believe that TDO measurements provide a very sensitive way to distinguish between local and itinerant moment magnetic orders. Local moment antiferromagnets do not show a peak at the Néel temperature, TN, but only a sharp decrease of χ below TN due to the loss of spin-disorder scattering changing the penetration depth of the ac excitation field. Furthermore, we show that the TDO is capable of detecting changes in spin order as well as metamagnetic transitions. Finally, critical scaling of χ (T, H) in the vicinity of TC is discussed in CeVSb3 and CeAgSb2.
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U2 - 10.1016/j.jmmm.2007.06.018
DO - 10.1016/j.jmmm.2007.06.018
M3 - Article
AN - SCOPUS:35448988596
SN - 0304-8853
VL - 320
SP - 354
EP - 363
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
IS - 3-4
ER -