Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Engineering

Selected Works

Shi Xue Dou

2014

Compounds

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Pressure Induced Magneto-Structural Phase Transitions In Layered Rmn2x2 Compounds (Invited), Shane Kennedy, Jianli Wang, Stewart Campbell, Michael Hofmann, S X. Dou Oct 2014

Pressure Induced Magneto-Structural Phase Transitions In Layered Rmn2x2 Compounds (Invited), Shane Kennedy, Jianli Wang, Stewart Campbell, Michael Hofmann, S X. Dou

Shi Xue Dou

We have studied a range of pseudo-ternaries derived from the parent compound PrMn2 Ge 2, substituting for each constituent element with a smaller one to contract the lattice. This enables us to observe the magneto-elastic transitions that occur as the Mn-Mn nearest neighbour distance is reduced and to assess the role of Pr on the magnetism. Here, we report on the PrMn2 Ge 2−xSix, Pr1−xYxMn2 Ge 2, and PrMn2−xFex Ge 2 systems. The pressure produced by chemical substitution in these pseudo-ternaries is inherently non-uniform, with local pressure variations dependent on the local atomic distribution. We find that concentrated chemical substitution …


Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu Oct 2014

Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu

Shi Xue Dou

The magnetic properties of a set of LaFe13−x−yCoySix compounds (x = 1.6 − 2.6; y = 0, y = 1.0) have been investigated using magnetic measurements, thermal expansion, 57Fe Mössbauer spectroscopy and high resolution neutron powder diffraction methods over the temperature range 10–300 K. The natures of the magnetic transitions in these LaFe13−x−yCoySix compounds have been determined. The Curie temperatures of LaFe13−xSix were found to increase with Si content from TC = 219(5) K for Si content x = 1.6 to TC = 250(5) K for x = 2.6. Substitution of Co for Fe in LaFe10.4Si2.6 resulted in a further …


Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou Oct 2014

Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou

Shi Xue Dou

Structural and magnetic properties of NdMn2−x Cu xSi2 compounds (x = 0-1.0) have been investigated by high intensity x-ray and resolution neutron diffraction (3-450 K), specific heat, dc magnetization, and differential scanning calorimetry measurements. Substitution of Cu for Mn leads to an increase in the lattice parameter a but a decrease in c at room temperature. Two magnetic phase transitions have been found for NdMn2−x Cu xSi2 compounds with TN for the antiferromagnetic ordering of Mn-sublatttice and TC for the Nd-sublattice ferromagnetic ordering, respectively. TC increases significantly with increasing Cu content from 36 K at x = 0 to 100 …


Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou Mar 2014

Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou

Shi Xue Dou

The structural and magnetic properties of the intermetallic compounds NdMn2−xTixSi2(x = 0, 0.1, 0.2, and 0.3) have been studied by x-ray and high resolution neutron powder diffraction, specific heat, dc magnetization, and differential scanning calorimetry measurements over the temperature range 3–450 K. The Curie temperature and Néel temperature of NdMn2Si2 decrease from TC = 36 K and TN = 380 K to TC = 14 K and TN = 360 K, respectively, on substitution of Ti (x = 0.3) for Mn. The magnetocaloric effect at the first order ferromagnetic phase transition at TC, has been investigated in detail. Under a …


Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou Mar 2014

Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou

Shi Xue Dou

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr0.5Y0.5Mn 2Ge2. In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (TCPr). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase …


Band Structure, Magnetic, And Transport Properties Of Two Dimensional Compounds Sr2-Xgdxcoo4, Q W Yao, Xiaolin Wang, H Kimura, S X. Dou, Konstantin Konstantinov, Z X. Cheng, F Hong, H Zhao, H Qiu, Kiyoshi Ozawa Mar 2014

Band Structure, Magnetic, And Transport Properties Of Two Dimensional Compounds Sr2-Xgdxcoo4, Q W Yao, Xiaolin Wang, H Kimura, S X. Dou, Konstantin Konstantinov, Z X. Cheng, F Hong, H Zhao, H Qiu, Kiyoshi Ozawa

Shi Xue Dou

The layered perovskite compound Sr2-xGdxCoO 4 has not yet been subjected to detailed study so far. In this report, structures, transport, magnetic properties, and first principle calculations will be reported for the two dimensional compounds Sr 2-xGdxCoO4 (x 0.5, 0.75, 1, 1.25). Rietveld refinement revealed that these compounds are crystallized in K2NiF 4-type structures with space group I4/mmm. It was found that the lattice parameter c decreases as x increases. Through the Curies Weiss fitting of the temperature dependent magnetization, it was found that the Sr 1.25Gd0.75CoO4 sample exhibits a weak ferromagnetic to paramagnetic transition at about 62 K, with …