Applied Physics

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Applied Physics

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Browsing Applied Physics by Subject "Alloy system"

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    Magnetic behaviour of the Cr-Al alloy system around the triple point
    (South African Institute of Physics, 2011) Sheppard, C.J; Prinsloo, A.R.E.; Alberts, H.L.; Strydom, A.M.; Muchono, Blessed
    Electrical resistivity and specific heat measurements on a series of Cr1-xAlx (0 ≤ x ≤ 0.034) alloy single crystals are reported. The results indicate that the triple point, where the incommensurate and commensurate spin-density-wave phases coexist with the paramagnetic phase, is situated close to T = 0 K on the magnetic phase diagram.
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    Magnetic properties of the (Cr -xAlx) V alloy system
    (South African Institute of Physics, 2013) Muchono, Blessed; Sheppard, C.J; Prinsloo, A.R.E.; Alberts, H.L.
    Electrical resistivity (), Seebeck coefficient (S) and magnetic susceptibility () measurements as a function of temperature on the (Cr -xAlx) V alloy system, with 0 < x are reported. Néel temperatures (TN) obtained from all these measurements decrease with Al concentration, disappearing near x  1.5, again reappearing for x  . (T) and S(T) for samples with x  6.1 show weak anomalies making the determination of TN difficult. However, these anomalies are sharply defined in (T), proving that it is an important tool in probing antiferromagnetic in this system. The present results show that the addition of just 1 at.% V to the Cr -xAlx alloy system suppresses antiferromagnetism in the concentration range 5 ≤ x ≤ . This behaviour is similar to that observed for the (Cr -xAlx) 5Mo5 alloy system.
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    Magnetic susceptibility studies of the (Cr98.4Al1.6)100-x Mox alloy System
    (South African Institute of Physics, 2014) Muchono, Blessed; Sheppard, C.J; Prinsloo, A.R.E.; Alberts, H.L.
    The magnetic susceptibility as a function of temperature, 𝜒𝜒(𝑇𝑇), on a spin-densitywave antiferromagnetic (Cr98.4Al1.6)100-xMox alloy system in the concentration range 0 ≤ x ≤ 8.8 is reported in order to investigate the possibility of quantum critical behaviour in this alloy system. Néel temperatures, TN, obtained from 𝜒𝜒(𝑇𝑇) measurements decrease with Mo concentration and sharply tend towards 0 K at a critical concentration xc ≈ 4.5. Antiferromagnetism is suppressed to below 4 K in alloys with x ≳ 4.5. Alloys in the concentration range 0 ≤ x ≤ 3.0 depict an upturn in the 𝜒𝜒(𝑇𝑇) curves just above the Néel temperature. The upturn is attributed to local magnetic moments formed around the impurity atoms. The magnetic phase diagram of the alloy system points towards the existence of a quantum critical point at the critical concentration x = xc. The suggestion of quantum critical behaviour in this alloy system from previous electrical resistivity(𝜌𝜌), Seebeck coefficient (𝑆𝑆) and specific heat (𝐶𝐶p) measurements is corroborated in this study.