Magnetic properties and underlayer thickness in SmCo/Cr films

Abstract

SmCo films with a Cr underlayer have been investigated as potentially attractive candidates for high density recording media. Magnetron sputtering was used here to produce Cr/SmCo x /Cr films on Si ͑100͒ substrates. The magnetic films were deposited at a substrate temperature of 350°C and an Ar pressure of 5 mTorr. Cr underlayers were deposited both at 25°C and at 350°C and exhibited different textures. Layer thicknesses were evaluated using Rutherford backscattering spectroscopy, while SmCo grain size and underlayer texture were determined from a Rietveld analysis of x-ray diffraction data. The magnetic properties were measured with a vibrating sample magnetometer. The resulting films had in-plane coercivities in the range 4-8 kOe. For a SmCo layer with a thickness of 200 nm, the Cr underlayer thickness was varied in the range 75-300 nm to study its effect on intergranular coupling in the films. For thermally demagnetized samples, both magnetizing and demagnetizing remanence curves were measured and used to evaluate switching field distributions and ␦m plots. The underlayer texture was found to affect magnetic properties more strongly than underlayer thickness.

Thick-film permanent magnets by membrane electrodeposition

“…The scaling of the magnetic forces can be explained as follows. The magnetic dipole field ͑stray field͒ of a magnet B ϳ 0 mr −3 is scale invariant-the magnetic moment m of an element of magnetization M scales as k −3 , whereas the magnetic field B falls off as r −3 , which scales as k 3 . However, the magnetic moment of a coil, m coil ϳ IA ϳ jaA where a is the conductor cross section and A is the coil area, scales as k −4 , hence the magnetic field scales as k −1 .…”

Cr缓冲层对SmCo/Cu薄膜结构及形貌的影响

“…Singh 等人 [15] 的研究表明, PLD 法制备 SmCo 薄膜中, 低的沉积速 [16][17][18][19][20] . 近年来, 一些工作报道了 Cr 层厚度对 SmCo/Cr 薄膜磁性能的影响 [21,22] , 我们通过实验研究了 Cr 缓 冲层厚度对 SmCo/Cu 薄膜磁性和结构的影响, 如图…”

Beneficial effect of rapid recurrent thermal annealing on magnetic properties of SmCo-based films

“…Lots of efforts have been put into the research about the sputtered SmCo-based films [4][5][6][7][8][9][10]. It is found that the SmCo-based films prepared by conventional sputtering and subsequent annealing process are almost amorphous and the crystallization is hard to be completed, which decides that the magnetic properties of these SmCo-based films are insensitive to heat treatment [4,5].…”