Designed synthesis of materials for high-sensitivity geomagnetic sensors

Ding, L.; Teng, J.; Wang, X. C.; Feng, C.; Jiang, Y.; Yu, G. H.; Wang, S. G.; Ward, R. C. C.
February 2010
Applied Physics Letters;2/1/2010, Vol. 96 Issue 5, p052515
Academic Journal
A structure of Ta/MgO/NiFe/MgO/Ta was designed and synthesized, which combines the advantages of both tunnel magnetoresistance materials with high magnetic field sensitivity and anisotropic magnetoresistance materials with high directional sensitivity. The magnetoresistance ratio in the device with structure of Ta(5)/MgO(4)/NiFe(10)/MgO(3)/Ta(3) (thicknesses in nanometers) increases with an increase in annealing temperature, reaching a maximum value of 3.5% at 450 °C, and then decreases with a further increase in annealing temperature. Meanwhile, a high sensitivity of 2.1%/Oe is obtained. The higher magnetoresistance ratio and sensitivity come from the significant specular reflection of electrons at both interfaces due to the crystalline MgO layer together with the sharp interfaces with the NiFe layer.


Related Articles

  • Single domain Bi2Se3 films grown on InP(111)A by molecular-beam epitaxy. Guo, X.; Xu, Z. J.; Liu, H. C.; Zhao, B.; Dai, X. Q.; He, H. T.; Wang, J. N.; Liu, H. J.; Ho, W. K.; Xie, M. H. // Applied Physics Letters;4/15/2013, Vol. 102 Issue 15, p151604 

    We report the growth of single-domain epitaxial Bi2Se3 films on InP(111)A substrate by molecular-beam epitaxy. Nucleation of Bi2Se3 proceeds at steps, so the lattices of the substrate play the guiding role for a unidirectional crystalline film in the step-flow growth mode. There exists a strong...

  • Thickness dependence of the mobility at the LaAlO3/SrTiO3 interface. Bell, C.; Harashima, S.; Hikita, Y.; Hwang, H. Y. // Applied Physics Letters;6/1/2009, Vol. 94 Issue 22, p222111 

    The electronic transport properties of a series of LaAlO3/SrTiO3 interfaces were investigated, and a systematic thickness dependence of the sheet resistance and magnetoresistance was found for constant growth conditions. This trend occurs above the critical thickness of four unit cells, below...

  • Rashba spin-orbit effect on the zero conductance and the magnetoresistance of a quantum ring. Dong, Yan-Kun; Li, Yu-Xian // Journal of Applied Physics;Jun2008, Vol. 103 Issue 11, p113716 

    Using a mode matched scattering matrix method, we study the effect of Rashba spin-orbit coupling and a tunnel barrier on the zero conductance and the tunnel magnetoresistance (TMR) in a one-dimensional conducting Aharonov–Bohm ring symmetrically coupled to two ferromagnetic leads. It is...

  • Microscopic structures of MgO barrier layers in single-crystal Fe/MgO/Fe magnetic tunnel junctions showing giant tunneling magnetoresistance. Mizuguchi, M.; Suzuki, Y.; Nagahama, T.; Yuasa, S. // Applied Physics Letters;6/19/2006, Vol. 88 Issue 25, p251901 

    The microscopic structures of MgO(001) barrier layers in magnetic tunnel junctions showing giant tunneling magnetoresistance were characterized by in situ scanning tunneling microscopy. The MgO thin films formed exceedingly flat surfaces, and their terraces were made even flatter by annealing...

  • Evidence for spin injection in a single metallic nanoparticle: A step towards nanospintronics. Bernand-Mantel, A.; Seneor, P.; Lidgi, N.; Muñoz, M.; Cros, V.; Fusil, S.; Bouzehouane, K.; Deranlot, C.; Vaures, A.; Petroff, F.; Fert, A. // Applied Physics Letters;8/7/2006, Vol. 89 Issue 6, p062502 

    We have fabricated nanometer-sized magnetic tunnel junctions using a conductive tip nanoindentation technique in order to study the transport properties of a single metallic nanoparticle. Coulomb blockade effects show clear evidence for single-electron tunneling through a single 2.5 nm Au...

  • Enhanced grain surface effect on the temperature-dependent behavior of spin-polarized tunneling magnetoresistance of nanometric manganites. Dey, P.; Nath, T. K. // Applied Physics Letters;10/17/2005, Vol. 87 Issue 16, p162501 

    We have investigated the effects of nanometric grain size on magnetoresistance (MR), especially on its temperature-dependent behaviors of single-phase nanocrystalline granular La0.7Sr0.3MnO3 and La0.7Ca0.3MnO3 samples with an average grain size in the nanometric regime (12 and 17 nm). Most...

  • First principles study of the magnetic properties of LaOMnAs. Shuai Dong; Wei Li; Xin Huang; Elbio Dagotto // Journal of Applied Physics;2014, Vol. 115 Issue 17, p17D723-1 

    Recent experiments reported giant magnetoresistance at room temperature in LaOMnAs. Here, a density functional theory calculation is performed to investigate magnetic properties of LaOMnAs. The ground state is found to be the G-type antiferromagnetic order within the ab plane but coupled...

  • Disorder-induced linear magnetoresistance in (221) topological insulator Bi2Se3 films. He, H. T.; Liu, H. C.; Li, B. K.; Guo, X.; Xu, Z. J.; Xie, M. H.; Wang, J. N. // Applied Physics Letters;7/15/2013, Vol. 103 Issue 3, p031606 

    A linear magnetoresistance (LMR) with strong temperature dependence and peculiar non-symmetry with respect to the applied magnetic field is observed in high-index (221) Bi2Se3 films. Different from the LMR observed in the previous studies which emphasize the role of gapless linear energy...

  • Peculiar magnetic and electrical properties near structural percolation in metal-insulator granular layers. Sousa, J. B.; Santos, J. A. M.; Silva, R. F. A.; Teixeira, J. M.; Ventura, J.; Freitas, P. P.; Cardoso, S.; Pogoreiov, Yu. G.; Kakazei, G. N.; Snoeck, F.; Araújo, J. P. // Journal of Applied Physics;10/1/2004, Vol. 96 Issue 7, p3861 

    We study CoFe/Al2O3 multilayers, varying from granular to continuous structure with CoFe nominal thickness (10 Ã… ⩽t ⩽18 Ã…). Structural percolation takes place at t =tc&assymp; 18 Ã…, changing from activated to metallic conductance. A sharp anomaly in ac coercivity of...


Read the Article

Courtesy of your local library

Public Libraries Near You (See All)
Looking for a Different Library?

Other Topics