Magnetization reversal under nonuniform magnetic fields at conditions relevant to magnetic random access memory applications

Kim, K. S.; Lee, C. F.; Lim, S. H.
November 2003
Applied Physics Letters;11/3/2003, Vol. 83 Issue 18, p3761
Academic Journal
Magnetization reversal behavior is examined under various nonuniform fields, the conditions of which are relevant to magnetic random access memory applications. During the magnetization reversal, the end domains play a key role at a uniform field, but they play a negligible role at a nonuniform field. Instead, a ripple pattern is initially formed in the interior and it progresses to form a vortex, resulting in a reversed domain. The switching field is found to be greater in the case of a nonuniform field, but, under a bias field, it is reduced greatly to a level similar to that for a uniform field. This result may indicate a wide window for the bit selectivity under a nonuniform field in magnetic random access memory applications. © 2003 American Institute of Physics.


Related Articles

  • Micromagnetic study on write operation in submicron magnetic random access memory cell. Asada, H.; Matsuyama, K.; Taniguchi, K. // Journal of Applied Physics;4/15/1996, Vol. 79 Issue 8, p6646 

    Presents information on a study which determined the binary bit states of storage cells in a spin-valve random access memory by the magnetization direction in the free magnetic layer. Analysis of the write operation of a submicron memory cell; Methodology of the study; Results and discussion.

  • Low write-current magnetic random access memory cell with anisotropy-varied free layers. Fukami, S.; Honjo, H.; Suzuki, T.; Ishiwata, N. // Journal of Applied Physics;Dec2008, Vol. 104 Issue 11, p113901 

    We propose a magnetic random access memory (MRAM) cell that utilizes field-induced switching and is applicable to high-speed memories. The MRAM cell, called the shape-varying MRAM cell, has three free layers, each having different shapes and functions, and achieves low write-current switching...

  • Effect of cap layer thickness on the perpendicular magnetic anisotropy in top MgO/CoFeB/Ta structures. Cheng, Chih-Wei; Feng, Wuwei; Chern, G.; Lee, C. M.; Wu, Te-ho // Journal of Applied Physics;Aug2011, Vol. 110 Issue 3, p033916 

    The perpendicular magnetic anisotropy of a series of top MgO/CoFeB/Ta layers is studied. Similar to the bottom Ta/CoFeB/MgO structure, the critical thickness of CoFeB is limited in a range of 1.1-1.7 nm. However, the cap layer shows much sensitive effect. Not only the type of material is...

  • Improvement switching characteristics of toggle magnetic random access memory with dual polarity write pulse scheme. Yuan-Jen Lee; Chien-Chung Hung; Ding-Yeong Wang; Cheng-Tyng Yen; Wei-Chuan Chen; Shan-Yi Yang; Kuei-Hung Shen; Yung-Hung Wang; Yung-Hsiang Chen; Ming-Jer Kao; Ming-Jinn Tsai // Applied Physics Letters;1/15/2007, Vol. 90 Issue 3, p032503 

    The writing probability of toggle magnetic random access memory (MRAM) at built-in bias field is studied by micromagnetic simulation and a dual polarity write pulse scheme has been proposed to enhance the toggle probability at low writing field. The critical writing field can be reduced to 19 Oe...

  • Micromagnetic simulations of nanosecond magnetization reversal processes in magnetic nanopillar. Finocchio, G.; Carpentieri, M.; Azzerboni, B.; Torres, L.; Martinez, E.; Lopez-Diaz, L. // Journal of Applied Physics;4/15/2006, Vol. 99 Issue 8, p08G522 

    In this paper we study by means of the spin torque model the fast switching behavior of the Co(20 nm)/Cu(5 nm)/Co(2.5 nm) magnetic multilayers of two different cross sections: ellipse (130×70 nm2) and ellipse (130×40 nm2). Simulations have been performed at zero and room (300 K)...

  • Effective bit addressing times for precessional switching of magnetic memory cells. Schumacher, H. W.; Chappert, C.; Sousa, R. C.; Freitas, P. P. // Journal of Applied Physics;6/15/2005, Vol. 97 Issue 12, p123907 

    We study the effective reversal times for bit-addressed precessional switching of the magnetization in magnetic random access memories (MRAMs). In our experiments the ultrafast magnetization dynamics of the free layer of a microscopic magnetic tunnel junction cell is accessed by means of...

  • Investigations of half and full select disturb rates in a toggle magnetic random access memory. Robertazzi, R. P.; Worledge, D. C.; Nowak, J. // Applied Physics Letters;5/12/2008, Vol. 92 Issue 19, p193309 

    Immunity to half select disturbs and self-activated toggle errors were measured for toggle magnetic memory cells at high switching speeds (200 ps rise time pulses, 100 ns in duration). Measurements of the immunity of cells to word line or bit line half selects indicate lifetimes for magnetic...

  • Ballistic bit addressing in a magnetic memory cell array. Schumacher, H. W. // Applied Physics Letters;7/25/2005, Vol. 87 Issue 4, p042504 

    A ringing free bit addressing scheme for magnetic memories like magnetic random access memory (MRAM) is proposed. As in standard MRAM addressing schemes the switching of a selected cell is obtained by the combination of two half-select field pulses. Numerical solutions of a single spin model of...

  • Composite free layer for high density magnetic random access memory with lower spin transfer current. Meng, Hao; Wang, Jian-Ping // Applied Physics Letters;10/9/2006, Vol. 89 Issue 15, p152509 

    A magnetic tunnel junction (MTJ) structure with a composite free layer consisting of a nanocurrent-channel (NCC) layer sandwiched by two CoFe layers was proposed and investigated. The NCC layer increased the local spin current density inside the free layer and thus enhanced the writing...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics