Magnetoelastic study of amorphous Fe90+xZr10−x alloys

Balakrishnan, Kalpana; Babu, P. D.; Ganesan, V.; Srinivasan, R.; Kaul, S. N.

doi:10.1016/s0304-8853(02)00368-2

Cited by 6 publications

(3 citation statements)

References 40 publications

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“…Recognizing that the thermoelastic martensitic transformation causes the shape memory effect [2][3][4][5][6][7] and the thermoelastic nature of MT is directly reflected 4,5,8 in the elastic property measurements across the austenite-martensite phase transformation, extensive measurements of 3 dynamic elastic properties, such as sound velocity and attenuation, of the sample q-Fe 20 were undertaken, using the vibrating reed technique [9][10][11]…”

mentioning

confidence: 99%

Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni–Fe–Al alloy

Mukhopadhyay

Kaul

2008

Applied Physics Letters

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Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of austenite (martensite) phase while cooling (heating), the results of an extensive ac susceptibility, sound velocity and internal friction investigation of the thermoelastic martensitic transformation in melt-quenched (sitedisordered) 25 20 55

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confidence: 99%

Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni–Fe–Al alloy

Mukhopadhyay

Kaul

2008

Applied Physics Letters

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“…T C decreases linearly with increasing pressure with a rate of −100 K GPa −1 (listed in Table I). For Fe 91 Zr 9 , a dT C /dp value of −30 K GPa −1 was reported from indirect Young's modulus measurements [58], while for Fe 90 Zr 10 , values of −38 [59][60][61], −60 [35], and −64 [62] K/GPa were deduced from the observed change in T C when pressure is applied. A dlnT C /dp value of −0.15 GPa −1 was determined for Fe 91 Zr 9 indirectly from forced-volume magnetostriction measurements [63].…”

Section: Resultsmentioning

confidence: 99%

Influence of the critical Fe atomic volume on the magnetism of Fe-rich metallic glasses evidenced by pressure-dependent measurements

et al. 2016

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Despite the intensive studies for decades, it is still not well understood how qualitatively different magnetic behaviors can occur in a narrow composition range for the Fe-rich Fe-transition metal (TM) amorphous alloys. In this study of amorphous Fe 100−x Zr x (x = 7, 9, 12) metallic glasses, normal ferromagnetism (FM) is found at 12 % Zr where only the FM-paramagnetic (PM) transition is observed at the Curie temperature, T C . In contrast, spin-glass (SG)-PM transition at a temperature, T g , called SG temperature, is only observed at 7 % Zr, while in the transient re-entrant composition range (x = 8−11), an SG-FM transition at a temperature, T f , called spin-freezing temperature, is also observed at low temperature besides the normal FM-PM transition at T C . In order to understand this unusual behavior, a detailed characterization of pressure (atomic volume), composition, and temperature dependence of the magnetic properties is coupled with high pressure synchrotron x-ray diffraction determination of the pressure dependence of the atomic volume. The results on Fe 100−x Zr x (x = 7, 9, 12) are compared to those obtained for the FM Co 91 Zr 9 metallic glass not showing any kind of anomalous magnetic properties. It is confirmed that the unusual behavior is caused by a granularlike magnetic structure where weakly coupled magnetic clusters are embedded into a FM bulk matrix. Since the mechanism of the magnetization reversal was found to be of the curling type rather than homogeneous rotation, the energy barrier determining the blocking temperature of the clusters is calculated as AR, where A is the exchange constant and R is the cluster size, in contrast to the usual characterization of the energy barrier by KV where K is the anisotropy energy and V is the cluster volume. The volume fraction of the FM part is a fast changing function of the bulk composition: Almost 100% FM fraction is found at 12 % of Zr while no trace of real FM is observed at 7 at % Zr. The driving force of this surprising magnetic character is the atomic volume: The lower the Zr content, the higher is the fraction of Fe atoms with compressed atomic volume having low magnetic moment. The percolation of their network separates the clusters from the FM bulk. The complex magnetic behavior of the Fe-rich Fe-Zr amorphous system at low temperatures can thus be interpreted with the only assumption of a cluster-size distribution and a weak coupling of the clusters to the FM matrix. The introduction of this coupling is able to explain the opposite pressure dependence of T g and T f . The threshold atomic volume in the low magnetic moment regions is found to be comparable to the atomic volume characteristic to the low-spin limit of the face-centered-cubic Fe alloys. The extensive literature results on the anomalous magnetism for various Fe-rich Fe-TM amorphous alloys and especially for the Fe-rich Fe-Zr glassy system are also found to be in agreement with this granular magnetic behavior.

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“…Bulk FeZr has been a subject of basic research for decades, both due to its interesting properties [23][24][25][26] and as a model system for noncollinear magnetism [27,28]. In recent years, this material has been used to explore the thin-film physics of amorphous structures [29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Reversed interface effects in amorphous FeZr/AlZr multilayers

et al. 2014

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We report an anomalous enhancement of the critical temperature (T c ) when the thickness (d) of the magnetic layer is decreased from 60 to 20Å in amorphous FeZr/AlZr multilayers. Further reduction of the thickness causes a decrease of T c , as expected by finite-size scaling, while the magnetic moment decreases monotonically for all values of d. The increase of the critical temperature is attributed to a reversed interface effect where local changes in the nearest-neighbor distance and coordination number gives a higher effective magnetic coupling at the interfaces compared to the interior of the layer. We have successfully described the results within a model where such interface effects are combined with finite-size scaling.

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Magnetoelastic study of amorphous Fe90+xZr10−x alloys

Cited by 6 publications

References 40 publications

Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni–Fe–Al alloy

Dynamic elastic properties and magnetic susceptibility across the austenite-martensite transformation in site-disordered ferromagnetic Ni–Fe–Al alloy

Influence of the critical Fe atomic volume on the magnetism of Fe-rich metallic glasses evidenced by pressure-dependent measurements

Reversed interface effects in amorphous FeZr/AlZr multilayers

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