skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Search for: All records

Creators/Authors contains: "Yakubu, Emmanuel"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. We report a systematic investigation of anisotropic magnetocaloric effects in a crystalline, monoclinic Cr3Te4 sample grown by the chemical vapor transport (CVT) method. The maximum magnetic entropy change −ΔSmaxM is 3.31 J kg−1 K−1 for the c axis (3.16 J kg−1 K−1 for the ab-plane) and the relative cooling power (RCP) is 340 J kg−1 for the c axis (350 J kg−1 for the ab-plane) near the Curie temperature with a magnetic field (μ0H) change of 9 T. With the scaling analysis of ΔSM, all rescaled ΔSM(T, H) curves collapse onto a single universal curve, indicating a second-order magnetic phase transition in Cr3Te4. Furthermore, −ΔSmaxM follows the power law of Hn with n = 0.656 ± 0.005. The RCP and δTFWHM have Hc and Hb dependence on field, with c = 1.179 ± 0.011 and b = 0.498 ± 0.005, respectively, which led us to estimate the critical exponents of β = 0.359 ± 0.013, γ = 1.646 ± 0.057, and δ = 5.578 ± 0.190. 
    more » « less
  2. Single crystal Cr1.27Te2 samples were synthesized by using the chemical vapor transport method. Single crystal x-ray diffraction studies show a trigonal crystal structure with a P3̄m1 symmetry space group. We then systematically investigate magnetic properties and critical behaviors of single crystal Cr1.27Te2 around its paramagnetic-to-ferromagnetic phase transition. The Arrott plot indicates a second-order magnetic phase transition. We estimate critical exponents β = 0.2631 ± 0.002, γ = 1.2314 ± 0.007, and TC = 168.48 ± 0.031 K by using the Kouvel–Fisher method. We also estimate other critical exponents δ = 5.31 ± 0.004 by analyzing the critical isotherm at TC = 168.5 K. We further verify the accuracy of our estimated critical exponents by the scaling analysis. Further analysis suggests that Cr1.27Te2 can be best described as a quasi-2D Ising magnetic system. 
    more » « less