39

Dielectric Dispersion of Triglycine
Sulfate at Low Frequencies
By

MitsuoIDA* andShujiKAWADAキ(RecievedJanuary20，1961)

1. Introduction
Studies on the dielectri
cdispersionoftr
iglycinesul
fateat low frequencies
have notbeen fullyr
eported. Since i
thasbeen suggestedt
hat the ferroelectr
icityofthecrystalofthi
scompoundmay be due to the hydrogen bond like that oft wasthought interestin
gt
ostudy thedielectri
cdispersiono
f theRochelles
alt，icrysta
lat low fr
equencies，andt
o compare it with t
hatof Rochelle salt whichesul
tofthestudy hasshownthe
hadbeenstudiedbythepresentaut
hors.1) The r
similarity ofthe twosubstances.

2.ExperimentalProcedure
The dielectri
cmeasurement at frequencies between 1kcjsand 1cjs wasdone.1)2)
by thesameapparatusd
escr
ibe
din apreceding paper
Singlecr
ystalsoftr
iglycinesul
fat
e were prep乱r
ed by the cooling and the010) and (001)plates about 2mm int
hickness cut fromevaporation methods，and (. The intensitiesofthe low frequency fieldthem wereusedi
nthemeasurement
werekept as low a
spossible but could not be lowered below 2.
5 Vjcm. Therelativ
e humidity waskept at about 17% duringthemeasurement.

3. ExperimentalResultandDiscussion(a) (010)plate

The experimental r
esults obtained with (010)platesar
e asfollows. Theart〆 oft
he complex dielectricrelationof therealpar
tピ andtheimaginary p
constant atsev
eraltemperaturesbelowtheCuriepointareshown inFig.1.
orr
ect
ion was not made for the dc
1n the calcu
lat
io
no
f the value of εク cconductance error because they were n
egl
igibl
y small compared to the totalconductance. FromF
ig. 1thereseemto be two disper
sionsasin Rochelles
altatesul
tobtained withthes
all1especill1en
temperaturesbelow theCuriepoint.1) The r
as theabovea
tt
ell1peraturesabov巴 the Curie point isshownin Fig.2， inwhich
the existenceo
ftwod
isper
sionsisveryeasil
yseen.
ComparingFig. 1andF
ig.2we f
indt
hat thev
aluesofげ aregenerallyl
ar
ger
*De
par
tmen
tofP
hys
ics，FacultyofScience，
KanazawaUniversity

五If， IDA 丘ndS.KAWADA

40xz

εq

2000

‑0ー ‑21"(、一一0 ‑ 1:7.5"C‑x‑46 C0。l411)
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OIJO

soo、、也、。
、也、一、、、 旬、、、h1、、、 ，、一一一一」一一一L一
一一一一一一‑‑'.
‑'‑一 一一一一一一一一
500

1000/よvOεfF
ig.1. Complex dielectricconstants旦tsev
eral.
temperaturesbelowtheCuriepointatt
巳mperaturesbelow the Curiepoint than above it. Thiscan not b色 attr
ibutedtot
he dcconductivity， which increasesas the temperaturer
ises. ThedifferenceofFig. 1and Fi
g. 2 can be explain巴d in another way asfollows. The seconddispεrsion(disper
sionat lowerfrequencies) occursa
tfre
quencies of thεorder ofa fewc/sinevery case. And thi
sstar
tin
gpoint islocate
d on the leftsideofthetopo
f the circulararcin the firstdispersiona
t temperatures below the Curie
pointandontherightsidea
t higher temperatures Thismeansthattherelaxation
固timeo
ffir
s
td
isper
sioni
s much longerat tempεratures below the Curie point
thanabove.

Dielectr
icDispersio
nofT
riglycineSulfatea
tLowF
requencies4
1e"
1000ー‑・‑48 Cー
同‑
<>
‑ー
‑50 C
00一
一 53 Cー‑
x

乙0

一・"

/.

.
l"
o

500/.0soo

ノ000/5
"
00

2000

Fig.
2. Complex dielectri
cconstantsa
tsev
er
al
temperaturesabovetheCuriepoint

The々ffec
tofpolingFig.3 showsthee
ffec
tofpoling. Curve(a)istheresul
twithavirgin sample.
Curve (b)isthe resu
lt withthe sample treate
dasfollow
s. The v
irgi
n sampleusedi
n the measurement (a) was polarize
din a dc fieldo
f1.1kV/cm for3
minutes，andmeasureda
fterthesample was aged for 3
0 minutes with the twoti
s found that the values ofε，and e'l decreasedelectrode
sshor
tc
ir
cuited. I

remarkably. When thesample wasd
epolarize
d by heatingi
tabove t
hecuriepoint
theeffecto
fthe polingnearlyd
isappear
ed.
Suche
ffec
twasa
ls
ofound wit
hRochel
1esalt.1) Drougard andYoung
め ど
have found tha
tthedielectr
ic con‑stan
to
fs
ingl
ecr
ystal
sof barium

一一・‑nou.polarIi'ed

1000titanatedecr
eases as the averageーー‑0‑‑ polarizeclpolarization decreases， and inter‑(a)preted thi
sfactas due to adomain

c1amping effect arisin
g from themultidomains
ituation. Soourresult
is contrary tot
heirs although thesample was notthesame kind. On
the otherhand FuruhataandKuro‑saki4) founds
imilareffectt
ooursinregardtotr
iglyc
in
esu
lfate，and at‑tr
ibute
ditt
othe motiono
fdomainwalla
stheyobservedv
ar
iat
iono
fthee
ffec
tbyvaryingthei
nte
nsityofthealter
nat
inge
lectr
i
cf
ielda
ppl
ied toz.

よ00 ト

3

f.

‑

f

10.

7(b)

$00

Fig.3
. Theeffec
tofpoling(25CO)/()OOεF

42

M. IDA andS KAWADA園thespecimen formeasurement. But wecould not detect any conspicuouse
ffectofield and suppos色d that the high dielectric constant ofthe
the intεns
ityo
f the Io the motiono
f domain walL These supnon‑polariz日dspecimen washardly due tposit
ion seemst
obesupported a
1soby thef
actt
hat the dielectri
cdispersionof
thesampleabove the Curie point is anomalous as below. Drougard and Young
t20kc/s， 出ld Furuhata and Kuro回 kia
t1
00c/
sand wemade the me旦surementaci
es lower than these，so we 巴xamined t
h色 dependence of theemployed frequ色neffec
tof polingon f
r
equ
en
c
i
es.Th巴 resulti
sshown inF
ig.4.

百d'
2。
了.
1
1
.←に

1
Il‑
‑‑‑‑‑
:‑"ml-pül~ri ，-叫。

οz/ノISO

7、よ¥/ρc/O.
20oO

ノ00

200soo/Kκ3κ/0氏"KSoKI<.

/fJO%

Fig 4. The dependenceo
fthee
ffεc
tofpolingon frequencies (41OC)
図Itis found t
hat the e
ffec
tof poling reversesit
s sign at the frequency ofncr
ease
sfrom 10kc/s t
o100kc/s bypoling.The
about 10kc/sandthe valueo
fピ ilatte
rfac
twillperhapsbe attributedto thepiezoelectri
coscillat
ionofthesample.
巴emsnot to beo
f thεlongitudinal but the bending typ邑 1nAnd thisoscillations
fthesample. Aftera
1
1 theeffec
tofpolings
巴emsviewofthe thickness (L7mm) oh
is seems to be the char
acter
ist
i
cfeatureofto bedecreaseo
f ピ and e久 And t
the ferroelectr
ics having hydrogen bond， but we must examine some other色rroelectr
icstobεsureabout it.
fTheeffectofX raydamage
TheCole‑Colediagramo
ftheX raydamaged specimen，exposedf
or6hourstoDielectr
icD
ister
s
io
nofTr
igl
yc
ineSul，fαtea
tLowFrequencies

43

40 kV5mAX raysfroma tungsten targeta
ta distanceo
f10 cm，is shown inFig.5.VVhen theX ray damaged cr
ystals were heatedabove theCurie pointand
cooled again theeffectof theX ray damages
tillremained.
ε"よ00・‑ー‑Virgin
一 0 ‑X rayed•"

ι4

ヨ之soo/000 E/Fig.
5. Complexd
ielectri
cconstantso
fX raydamagedsample (230C)
Similar fact
shavebeen already found in Rochelles
alts.l) Chynoweth5) studiedulfat
e and found the domain
the hysteresi
scurveofX ray damaged tr
iglycin巴 sclampinge
ffectof the radiation. He supposed t
hat the effectoft
he radiation
was tomodifyone minimum oft
hepotential energy diagram not occupied bytheion. But to explain our experimental r
esult we must presume the pot
ent
ial
minimumoccupiedby the ionalsosuffer
smodi
ficat
ion.

(b) (001)tlateIn thi
scasethevalueso
fe"weretoo sm旦11t
obe measured and so only the' were measured. The r
elationsof 〆 and frequency atseveral tempera‑
valueofetur
esareshown inF
ig.6.
巴ctr
i
cd
ispe
r
siona
t lowfrequ己n
cie
sa
lsoe
x
i
st
sin(001)
Itisseen t
hat the dieltseems toplates. As thedisper
sionoccursa
t frequencies lower than a few c/s，ibeo
fthesamekinda
sthe second dispersionin(010)plates.Fig.6 shows thatthisdispersion becomessmaller as the temperature r
ises. The e
ffec
t of the dc
electricf
iel
d was not detected butsomee
ffec
tof X ray damage wasnot
iced. We
have notyet succeededi
n thinkingouta m巴chanism which w
il
lexplain thefactsabout (010) and (001)plates.

M~ IDA and S.KAWADA

44εf4‑00

一叶一一 290 C‑ 0 ‑45cC‑ x ‑490C

司ー 0‑‑‑ 290C polarizecl‑‑‑‑x‑c‑‑ 29'C X‑rayedn300

之00100』ーーモ認ー‑ 、 火 、 、 九 、 、 a、ヲ ー，、~ーミι/‑x一一ベx‑‑̲̲，，̲ーー

10100Fig.6. The relations of e' and frequency

r:encesRefe1) M.
Ida andS.Kawada: Sci.Rep.KanazawaUniv.1(1960)552) M.
Ida.S.KawadaandTXesho: Sci.Rep.KanazawaUniv. 1(1960)5.DrougardandD.R.Young: Phys.Rev.94(1956)15613) M.E4) Y.FunユhataandS.Kurosaki: ReportedattheM邑etingo
fPhys.Soc.Japan (1959)
5) A.G.Chynoweth: Phys.Rev.113(1959)15ヲ