J Philip

Publications (4)41.99 Total impact

• Source

  Available from: Biswarup Satpati

  Article: Carrier-controlled ferromagnetism in transparent oxide semiconductors.

  J Philip, A Punnoose, B I Kim, K M Reddy, S Layne, J O Holmes, B Satpati, P R Leclair, T S Santos, J S Moodera
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  ABSTRACT: The search for an ideal magnetic semiconductor with tunable ferromagnetic behaviour over a wide range of doping or by electrical gating is being actively pursued as a major step towards realizing spin electronics. A magnetic semiconductor having a high Curie temperature, capable of independently controlled carrier density and magnetic doping, is crucial for developing spin-based multifunctional devices. Cr-doped In(2)O(3) is such a unique system, where the electrical and magnetic behaviour-from ferromagnetic metal-like to ferromagnetic semiconducting to paramagnetic insulator-can be controllably tuned by the defect concentration. An explicit dependence of magnetic interaction leading to ferromagnetism on the carrier density is shown. A carrier-density-dependent high Curie temperature of 850-930 K has been measured, in addition to the observation of clear magnetic domain structures in these films. Being optically transparent with the above optimal properties, Cr-doped In(2)O(3) emerges as a viable candidate for the development of spin electronics.
  Nature Material 05/2006; 5(4):298-304. · 32.84 Impact Factor
• Article: High-temperature ferromagnetism in Zn< sub> 1-</sub>< i> x Mn< i> x O semiconductor thin films

  N Theodoropoulou, V Misra, J Philip, P LeClair, G P Berera, J S Moodera, B Satpati, T Som
  Journal of Magnetism and Magnetic Materials 01/2006; 300(2):407-411. · 1.78 Impact Factor
• Article: Coexistence of ferromagnetism and superconductivity in Ni/Bi bilayers.

  P LeClair, J S Moodera, J Philip, D Heiman
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  ABSTRACT: In spite of a lack of superconductivity in bulk crystalline Bi, thin film Bi deposited on thin Ni underlayers are strong-coupled superconductors below approximately 4 K. We unambiguously demonstrate that by tuning the Ni thickness the competition between ferromagnetism and superconductivity in the Ni/Bi can be tailored. For a narrow range of Ni thicknesses, the coexistence of both a superconducting energy gap and conduction electron spin polarization are visible within the Ni side of the Ni/Bi bilayers, independent of any particular theoretical model. We believe that this represents one of the clearest observations of superconductivity and ferromagnetism coexisting.
  Physical Review Letters 02/2005; 94(3):037006. · 7.37 Impact Factor
• Article: Strong ferromagnetism in Zn_1-xMn_xO semiconducting thin films

  N Theodoropoulou, J Philip, P Leclair, G Berrera, J Moodera, B Satpati
  APS Meeting Abstracts. 01/2004; 1:26012.