3rd July, 2015 Dr. Eng. Yoshinobu Honkura, President 1 Magnedesign incorporation, Japan Vice president Magnetic society of Japan The study on electromagnetic coupling with amorphous wire and micro coil excited by GHz pulse current Outline 1. Background 2. The study on Micro coil performance excited by GHz pulse 3. Discussion on GHz-Spin-Rotation Effect(GSR) 4. Future scope and Summary the International Workshop on Magnetic Wires, IWMW 2015, Ordizia 203 July
31
Embed
The study on electromagnetic coupling with amorphous wire ... · The study on electromagnetic coupling with amorphous wire and micro coil excited by GHz pulse current Outline 1. Background
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
3rd July, 2015
Dr. Eng. Yoshinobu Honkura,President 1Magnedesign incorporation, Japan
Vice president Magnetic society of Japan
The study on electromagnetic coupling with amorphous wire and micro coil excited by GHz pulse current
Outline
1. Background
2. The study on Micro coil performance excited by GHz pulse
3. Discussion on GHz-Spin-Rotation Effect(GSR)
4. Future scope and Summary
the International Workshop on Magnetic Wires, IWMW 2015, Ordizia 203 July
Backgrond: Development History on GMI Sensor
amorphous
wire
20μ
human hair
150μm
Prof. Masumoto Prof. Mohri
research of
Amorphous Wire
invention of
MI sensorDevelopment of
Micro coil
excited by GHZ pulse
Electronics compass
2×2×1㎜
0.9mm×0.5mm
Amorphous Wire 20μ
Development of
MEMS type MI element
MI sensor circuitFe-Co base Amorphous wire
Production of E-compass
Based on GMI sensor Study of Amorphous Wire
90 95 00 0580 85
Develop of GMI Sensor
MEMS type GMI elemnt
10
Discovery of
MI sensor
With Amorphous ribbon
Prof. Makhotkin
In USSR
0.20mm
0.2
5m
m
15
More sensitiveMore micro
MEMS type MI element
Honkura
MAGNEDEZIGN
Micro coil type MI element
MI Sensor
Aichi Steel AMI306
MI Sensor
Aichi Steel AMI307
GMR Sensor
ALPS HSCDT004A
TMR Sensor
Freescale MAG3110
Hall Sensor
ASAHI KASEI AK8975
GMR Sensor
YAMAHA YAS530
-10
-8
-6
-4
-2
0
2
4
6
8
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Accura
cy
[deg.
]
Accuracy : ±1.1°resolution: ±0.8°
Accuracy : ±1.9°resolution: ±0.5°
-10
-8
-6
-4
-2
0
2
4
6
8
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Err
or
[degre
e]
Accuracy: ±0.6°resolution: ±0.4°
Accuracy : ±0.3°resolution: ±0.3°
-10
-8
-6
-4
-2
0
2
4
6
8
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Acc
ura
cy [
degre
e]
-10
-8
-6
-4
-2
0
2
4
6
8
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Accura
cy
[degr
ee]
Accuracy : ±2.0°resolution: ±1.9°
-10
-8
-6
-4
-2
0
2
4
6
8
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Accura
cy
[degr
ee]
Accuracy : ±1.1°resolution: ±0.4°
-10-8-6
-4-2024
68
10
0 60 120 180 240 300 360
Azimuth [degree]
Azi
muth
Accura
cy
[deg.
]
Azimuth Accuracy of various type E-compass for Mobile Phone
4
Principle of GMI sensor
0.5GHz 80mA
10ns
0.5 ns
Pulse current Circular aligned spin
Magnetic Field Hex
0.5nm
-2
-1
0
1
2
-6 -4 -2 0 2 4 6
external magnetic field(G)
outp
ut vo
ltage (
V)
±3G
external magnetic field (G)
outp
utvo
ltage
(V)
1
1.2
1.4
1.6
1.8
2
-10 -5 0 5 10
±3G
Magneto-impedance vs magnetic field strength Coil voltage vs magnetic field strength
f: frequency N: coil numbers
The effect of coil turns of pick up coil of MI element
Authorized by Prof. Uchiyama
Coil numbers (turn)
Sensitiv
ity (
v/m
T)
The effect of the frequency of exciting current
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 1 2 3
Frequency (GHz)
Imagin
able
part o
f w
ire im
pedance (
%/Am
-1 )
0.4
Current pulse frequency 1GHz
t
impedance Imaginal part of impedance
using big size coil of diameter 3mm Using MEMS type coil of 30μm⇒What frequency is best for coil voltage
Measured by Prof. ZhukovMeasured by Prof. Mohri
10MHz is best
0.60mm
0.3
0m
m
Coil turns of 560
Develop the micro coil type of GMI sensor to increase coil numbers
0.40mm
0.2
5m
m
wet processCoil pitch of 30 μm
pT element for detecting bio-magnetism
Micro coil type for e-Compass
Coil turns of 42Coil turns of 16
0.20mm
0.2
5m
m
Coil turns of 42
0.90mm
0.5
0m
m
Aichi Steel type
dry processCoil pitch of 5.5 μm
New Process to produce the micro coil type GMI element
素子の製造プロセス
Principle of MI detection
Pulse currentrising time0.5nsec
Amorphous wire
External magnetic field Hex
Pick up Coil
etching Bottom coil pattern Wire setResin molding
Upper coil pattern
Coil pitch 5.5μm
GrooveW=25μmDepth=6μm
Wire Dia. 14μmSiO2 coating
Resin moldingCoil pitch 5.5μm
Production Process
9
Enlarged view of GMI element with the micro coil
Groove with Bottom coil pattern
Magnified figure with coil pitch of 5.5 μmGroove depth of 6μm
Coil
wireGlass
Enlarged view of Upper Coil pattern
Enlarged view ofBottom coil pattern
Detail section drawing
Aliment precision of <±1μmRotation precision of <±0.02degree
The amorphous wire aliment machine
11
Equipments in use at nanotechnology platform of Nagoya University
We can increase the sensitivity of GMI sensor by the coil numbers but Micro coil is accompanied by the
increase of the coil resistance which makes IR drop and decrease the coil voltage
3-5 The effect of Buffer circuit on coil voltage
Coil voltage decrease about 25% after buffer circuit.Not so big problem but need to develop suitable circuit
40mV/G
30mV/Gauss
two-wireCoil Numbers =42 turns
0.20mm
0.2
5m
mRising pulse
External Field (G)
Coil
Voltage (
V)
converted to arcsin(V/Vo)= πH/2Hm
3-6 new relationship on the output voltage against magnetic field
±12G
±36G
Using the equation , the measuring range can be extended from ±12G to ±36G.
V=V0sin(πH/2Hm )
-Hm +Hm
External magnetic field (G)External magnetic field (G)
Co
il vo
lta
ge
(V
)
Co
nve
rte
d C
oil
vo
lta
ge
(V
)
22
If spin rotation with angel of θ on the surface is detected by the micro coil,
Theoretical Eq. :V=Vo・sin(2θ) here tanθ=Hin/Kθ(Hk) ⇒θ is function of HkHin: effective magnetic field
Kθ:the intrinsic circular anisotropy magnetic field of the amorphous wire related to the intrincis logthdinal
anaisotoropy magnetic field Hk .
Experimental Eq. :V=Vo・sin(2φ) φ=πH/2Hm
⇒φ is function of Hm
two equation are same form
Experimenatal deta and theory sujest :Hm =Hk
theory eq and experimental eq are matched.
θ = φ
Circular spin aliment Magnetic field H
thickness
0.5 μm
α
converted voltage with Vt=arcsin (Vm/Vo)Raw Data
Hm
Co
il v
olt
age
Vm
(V)
Magnetic field H(G)Magnetic field H(G)
Co
nv
erte
d c
oil
vo
ltag
e (V
)
my hypothesis : Why is there V=V0sin(πH/2Hm ) between with V and H ?
1) BH curve of amorphous wire against X direction
Why is there V=V0sin(πH/2Hm ) between with V and H ?
Hk1 Hm1 Hm2Hk2 Hk3 Hm3990℃
980℃
990℃
980℃
M/Ms
Field HexOe
BHcurve
Curve of coil voltage
a)Bh curve of the amorphous wire
Magnetic properties of the amorphous wire have two types as longitudinal direction and circular direction
Coil voltage(mV)
Hk
β 10%
H
M
Ms
Why is Hk is equal to Hm
2) The coil voltage V vs magnetic field H
b)The coil voltage V vs magnetic field H
V=V0・sin(πH/2Hm)here Hm is defined as the field strength of V max
M= χHχ ≒ χo{1―β×(H/Hk)2}
Hk is defined as the field strength where the magnetization is caused by from magnetic domain movement to magnetization rotation.Hk is roughly defined as the field of M/Ms=90%.β gives the magnetic susceptibility at H=Hk
χo Χo(1-β)
Hm= αHk (α= 0.96)
When H=Hk, the core domain is saturated and spin in the surface domain reaches to the angle of π/4. If over π/4, the surface domain changes to the core domain. When H>Hk, the core domain extends forward the surface domain and spin angle rotates from π/4 to π/2 . That means when H=Hk, the coil voltage has the max and Hm=Hk.However experimental data shows Hm=0.96Hk. (α=0.96)becuaase the demagnetizing field in surface domain is alittle small compered to the core domain.
Kθ intrinsic internal magnetic fieldHin : internal magnetic field
Spin direction with θ
Spins Rotation with the θ at GHz speed gives V=Vo・sin(π/2×H/Hm)
Frequncy is givenAngular velocity ω=2πfSpin angle of θ (Mx=M0sinθ)Ms velocity : Vx=M02πfcosθ
1)Experimental Equ. V=V0sin2φ where φ= πH/4Hm
2) Theoretical Equ. V=V0sin2θ・ If spins with the angle of θ rotates at the high angular velocity of 2πf、 Coil voltage becomes V=V0sin 2θ.・The reason is;
The flux of x direction: φx= msLDdsinθ=φ0sinθ
The velocity of φx: Vx= 2πfcosθ
The coil voltage V=-dΦ/dt=- φx・VxV==-φ0・sinθ・cosθ・2πf=―V0・sin2θ
3)The spin angle of θ is defined astanθ=Hin/Kθ
Hin=H{1-Nχo+βNχo(H/Hk)2}4) When H=Hk ,θ=π/4 and Hin=Kθ