SAIP2014

Probing the antiferromagnetism in (Cr₈₄Re₁₆)_100-<i>y</i>V_<i>y</i> alloys using neutron diffraction

9 Jul 2014, 17:10

1h 50m

D Ring ground level

Board: A.74

Poster Presentation Track A - Division for Physics of Condensed Matter and Materials Poster2

Speaker

Mrs Bincy Susan Jacobs (University Of Johannesburg)

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

Yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

PhD

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

Sommerfeld coefficient (γ), obtained from fitting the low temperature specific heat (C_p) data to the equation C_p = γT+ βT³, has previously been used to identify the region of critical concentration in Cr_1-xV_x [1] and in (Cr₈₄Re₁₆)_100-yV_y [2] alloys. The effects of spin fluctuations and nature of the nesting bands on physical properties of Cr_1-xV_x alloys were explored using specific heat measurements and the corresponding trends in the γ – x curve [1]. In the (Cr₈₄Re₁₆)_100-yV_yalloy system, γ shows anomalous trends close to the critical concentration as well as at y ≈ 4 [2]. The decrease in γ observed at y ≈ 4 may correspond to the transition from one magnetic phase to another. At y = 0, the alloy system is expected to be in the commensurate spin-density-wave (CSDW) phase [3]. On increasing the V concentration, the incommensurate (I) SDW phase may prevail due to the mismatch between the electron and hole sheets. In order to clarify this conjecture, neutron diffraction studies are proposed. Neutron diffraction is an ideal tool to explore the magnetic phases in an alloy and was successfully used in the Cr_1-xRu_x system to establish the types of antiferromagnetic order in the system [4]. This paper reports on the preliminary results of neutron diffraction on the (Cr₈₄Re₁₆)_100-yV_y alloy system, with y = 0, 4.2 and 6.2. Results indicate that at room temperature, the Cr₈₄Re₁₆ alloy is in the CSDW phase. Possible magnetic satellites indicative of the ISDW phase were observed in the alloys with y = 4.2 and 6.2 as envisaged.
[1] Takeuchi J et al., J. Phys. Soc. Japan 49, 508 (1980)
[2] Jacobs B S et al., J. Appl. Phys. 113, 17E126 (2013)
[3] Fawcett E et al., Rev. Mod. Phys. 66 25 (1994)
[4] Papoular R et al., J. Magn. Magn. Mater.24 106-110 (1981)

Main supervisor (name and email)<br>and his / her institution

Prof ARE Prinsloo
alettap@uj.ac.za
University of Johannesburg

Peer reviewing

Paper

Accepted on 10 Mar 2015 by Steven Karataglidis

SAIP_2014_Revised-_5_Mar__2015.pdf