Title: ???????????????????????mgnetite,%20magnet???????????
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4???????????????????????mgnetite, magnet???????????
5???????????
???????????????? ????????????(1917?) ???3????????
?????????
Kichizaemon Sumitomo
?????????????? ?? ???????(1932?) KS??2???????
400600 Oe
Mishima Tokusu
Fe2O3?????????? ????????????(1931?) MK?????????
600900 Oe ???Phylips??BaO6Fe2O3?????(1952)
6????????(1960 )
USA ?????
Swiss
???USA (???????)
7???????
? ???????? (BH)MAX???? Nd-Fe-B? gt 55 MGOe ?
????????????????? ?????? gt 800 ? ? ?????? Fe???
8???????????
H
H
9 10?????
??????(??)? ????(??)
??????????? ???????(??mB??????) ??(??gauss,
A/m ??????)
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?????????????????????????????????????????????????
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????1930?????????????Bohr, Heisenberg, Dirac,
Shoredinger, Pauri,Born ??????
??????????????????1964?????Feynman,Shwinger??????
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19????? -?????????????-
20??????????????
??????(Spring-8 in ??)
??????????MRI
???????
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21???????????
22????????????
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23???????????????
? AFM???
???????(MEMS) ????
MEMSMicro Electro Mechanical System
Olympus Si ??????
1? \5000\10000
24MEMS????
?????????????????????????????
???????????????
25NdFeB???????????
????
- Nd2F14B 1983? ?????? ?????? ???????????
1996?????????????????????????
26NdFeB???????
1.22 nm
??????0.1mm??? ???????????1990??????????
????????????
- ????????? (200300nm)
- ??????????
0.882 nm
Nd
Fe
B
????????
??????
????????c???????? ??????????????(?10kOe)
????????????????? ??c????????
????
????
27Mo(100)??MBE???
??? as-roll?Mo???? X?????(100)???
???(200)
????lt110gt
28????
Cooling Water
In
Out
Substrate Holder
0.1 mm Glass Sheet
2 x 10-6 Torr
0.1 mm Mo
5 x 10-3 Torr
Fe sheet
Ar
casted Nd20Fe64B16
???????? ???
TARGET HOLDER
RF Sputtering Set Up
29???????
splutter ????????????????????????????????????
?????
??
1852??????????????????????????????????????????????
????????????????????????????????????????
???????(???????)
1?????????????????????????2????????????????????
?????????????????????????????3??????????????????
????????????????????????????????????????????
30Ti Coating 600 A
2 micron NdFeB Film
0.1 mm Mo Substrate - As rolled sheet - RMS 104
nm
Film Structure
Average Deposition Temperature (
T
)
T1 lt T2
T
lt T
1
2
T
T
2
1
t 0 mm
t 1.0 mm
Glass Insulation
Low Temp Deposition Ts 300oC ?
High Temp DepositionTs 365oC
Water cooled Cu substrate holder
??????????
31LTD as-depo??TEM?
Purely Amorphous
Mo (200)
Intensity (a.u.)
Ti (002)
Ti (100)
Mo (110)
2?
32HTD as-depo ??TEM?
NdO (black)
Mo (200)
Intensity (a.u.)
Ti (002)
Mo (110)
Amorphous Matrix
2?
33????????
Ku MsHc / 2
Ku 0.014 J/cm3
Ku 0.059 J/cm3
H // plane
Magnetization (kG)
H (kOe)
H (kOe)
HTD
LTD
34Annealing process
30 mins, 650oC, 6.7x10-4 Pa ???? hr x oC/min
(x 10 8)
Conditions for Vacuum Annealing IR Heating Type
Vacuum Furnace Vacuum Pressure 6.7 x 10-4 Pa
650oC, 30 min
50oC/min
Temperature (o C)
Furnace Cooling to Room Temp.
Annealing Time (min)
35SEM ?
Dense, continuous, no voids
fine crystals, some small voids surround the
large and elongated 0.5 µm crystallites.
36Anneal ?????
uniformly distributed grains with size 400 nm
plain view
hr 50oC/min
cross section
37Anneal ??????
Initial magnetization curve
4?M (kG)
H (kOe)
Nucleation type mechanism
38Assignment of particles in grain boundary
Amorphous matrix
Nd2Fe14B matrix
Particles Structure fcc (a 5 nm)
NdO
As deposited
Annealed Film annealed at 650oC
Matrix ????????NdO???
39Conclusions
- Annealing at 650oC/min.
- TEM Nd2Fe14B - ? phase NdO
- Nd2Fe14B grain 400 nm, near single domain,and
behaves as nucleation type magnet.
MEMS??????????
? (BH)MAX27 MGOe
- (BH)max 20 MGOe??
- Hc 15 kOe??
- Ir 1.0 T??
- ????????????????
- ?? 300 µm ??
- ?????(??????)
? iHc 17 kOe
? 4?Mr 10.6 kG, 4?Ms 11.2 kG
?
?
???? (????????????????????????)
40????????????????? ????????????????? ??????????
?????????? ?????????????????
41 ??? ????? 2.010-6 Torr
KrF???????(??248 nm ) ????20 ns ????1?
??????0.2,0.3,0.4,0.6 J/cm2
????????????
????? ??? ????400?
??????????100µm???????
42??????
???
????????X??????? ? ??????? 0.4 J/cm2 ??????
? ???????c?????
43??????????????
???? (??100µm)?????????
KrF??? ??????? 0.4 J/cm2 ????1?
?????
MO??????????
????????
44?????????
?????????
1992 IBM????????
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