Magnetic properties of submicron Ni-Mn-Ga martensitic thin films1

2004 ◽  
Vol 855 ◽  
Author(s):  
M. Kohl ◽  
V.A. Chernenko ◽  
M. Ohtsuka ◽  
H. Reuter ◽  
T. Takagi

ABSTRACTTwo series of Ni-Mn-Ga thin films with two different compositions and various thicknesses in the submicron range are investigated with respect to their structural and magnetic properties. The films are fabricated by sputter deposition on alumina substrates and subsequent heat treatment. The martensitic transformation occurs well above room temperature showing a small thermal hysteresis width of about 6 K. The magnetic properties turn out to be thickness-dependent in the submicron range. In particular, in-plane magnetic susceptibilities increase and critical field strengths for onset of saturation decrease for decreasing thickness down to 0.1 μm by factors of 3–5 depending on the chemical composition. The Curie temperature TC decreases by about 25 K for samples with TC higher than the martensitic transformation.

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.


2013 ◽  
Vol 690-693 ◽  
pp. 1702-1706 ◽  
Author(s):  
Shuang Jun Nie ◽  
Hao Geng ◽  
Jun Bao Wang ◽  
Lai Sen Wang ◽  
Zhen Wei Wang ◽  
...  

NiZn-ferrite thin films were deposited onto silicon and glass substrates by radio frequency magnetron sputtering at room temperature. The effects of the relative oxygen flow ratio on the structure and magnetic properties of the thin films were investigated. The study results reveal that the films deposited under higher relative oxygen flow ratio show a better crystallinity. Static magnetic measurement results indicated that the saturation magnetization of the films was greatly affected by the crystallinity, grain dimension, and cation distribution in the NiZn-ferrite films. The NiZn-ferrite thin films with a maximum saturation magnetization of 151 emucm-3, which is about 40% of the bulk NiZn ferrite, was obtained under relative oxygen flow ratio of 60%.


2021 ◽  
Vol 118 (15) ◽  
pp. 152402
Author(s):  
Sudhir Regmi ◽  
Zhong Li ◽  
Abhishek Srivastava ◽  
Rabin Mahat ◽  
Shambhu KC ◽  
...  

2014 ◽  
Vol 50 (8) ◽  
pp. 1-4 ◽  
Author(s):  
Robina Ashraf ◽  
Saira Riaz ◽  
Mahwish Bashir ◽  
Usman Khan ◽  
Shahzad Naseem

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Gui-fang Li ◽  
Shibin Liu ◽  
Shanglin Yang ◽  
Yongqian Du

We prepared magnetic thin films Ni81Fe19on single-crystal Si(001) substrates via single graphene layer through magnetron sputtering for Ni81Fe19and chemical vapor deposition for graphene. Structural investigation showed that crystal quality of Ni81Fe19thin films was significantly improved with insertion of graphene layer compared with that directly grown on Si(001) substrate. Furthermore, saturation magnetization of Ni81Fe19/graphene/Si(001) heterostructure increased to 477 emu/cm3with annealing temperatureTa=400°C, which is much higher than values of Ni81Fe19/Si(001) heterostructures withTaranging from 200°C to 400°C.


2002 ◽  
Vol 189 (3) ◽  
pp. 883-887
Author(s):  
Sam Jin Kim ◽  
Woo Chul Kim ◽  
In Bo Shim ◽  
Chul Sung Kim ◽  
Seung Wha Lee

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