6 research outputs found
Contact-less measurements of Shubnikov-de Haas oscillations in the magnetically ordered state of CeAgSb and SmAgSb single crystals
Shubnikov - de Haas oscillations were measured in single crystals of highly
metallic antiferromagnetic SmAgSb and ferromagnetic CeAgSb using a
tunnel diode resonator. Resistivity oscillations as a function of applied
magnetic field were observed via measurements of skin depth variation. The
effective resolution of p allows a detailed study
of the SdH spectra as a function of temperature. The effects of the Sm long -
range magnetic ordering as well as its electronic structure (-electrons) on
the Fermi surface topology is discussed
Distinguishing local moment versus itinerant ferromagnets: Dynamic magnetic susceptibility
Radio-frequency measurements of dynamic magnetic susceptibility of various ferromagnets show striking differences between local-moment ferromagnetism (LFM) and weak itinerant ferromagnetism (IFM) ferromagnetic systems. LFMs show a very sharp peak in susceptibility in the vicinity of the Curie temperatureTC that rapidly decreases in amplitude and shifts to higher temperature with the application of a weak dc bias field. In stark contrast, the generally accepted IFM systems show no peak, but rather a broad maximum well below TC. The temperature of this maximum shifts to lower values and the amplitude is suppressed with an applied dc field
Multiple nearest-neighbor exchange model for the frustrated magnetic molecules Mo72Fe30 and Mo72Cr30
Our measurements of the differential susceptibility dM/dH of the frustrated
magnetic molecules Mo72Fe30 and Mo72Cr30 reveal a pronounced dependence on
magnetic field (H) and temperature (T) in the low H - low T regime, contrary to
the predictions of existing models. Excellent agreement with experiment is
achieved upon formulating a nearest-neighbor classical Heisenberg model where
the 60 nearest-neighbor exchange interactions in each molecule, rather than
being identical as has been assumed heretofore, are described by a
two-parameter probability distribution of values of the exchange constant. We
suggest that the probability distribution provides a convenient
phenomenological platform for summarizing the combined effects of multiple
microscopic mechanisms that disrupt the idealized picture of a Heisenberg model
based on a single value of the nearest-neighbor exchange constant.Comment: 8 pages, 5 figure
Contactless measurements of Shubnikov-de Haas oscillations in the magnetically ordered state of CeAgSb2 and SmAgSb2 single crystals
Shubnikov-de Haas oscillations were measured in single crystals of highly metallic antiferromagnetic SmAgSb2 and ferromagnetic CeAgSb2 using a tunnel diode resonator. Resistivity oscillations as a function of applied magnetic field were observed via measurements of skin depth variation. The effective resolution of Delta rho similar or equal to 20 p Omega allows a detailed study of the SdH spectra as a function of temperature. The effects of the Sm long-range magnetic ordering as well as its electronic structure (4f electrons) on the Fermi surface topology is discussed.This article is published as Prozorov, Ruslan, Matthew D. Vannette, German D. Samolyuk, Stephanie A. Law, Sergey L. Bud’ko, and Paul C. Canfield. "Contactless measurements of Shubnikov-de Haas oscillations in the magnetically ordered state of Ce Ag Sb 2 and Sm Ag Sb 2 single crystals." Physical Review B 75, no. 1 (2007): 014413.
DOI: 10.1103/PhysRevB.75.014413.
Copyright 2007 American Physical Society.
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