TY - JOUR
T1 - Phase transition and temperature dependent electronic state of an organic ferroelectric, phenazine-chloranilic acid (1:1)
AU - Asaji, T.
AU - Seliger, J.
AU - Žagar, V.
AU - Sekiguchi, M.
AU - Watanabe, J.
AU - Gotoh, K.
AU - Ishida, H.
AU - Vrtnik, S.
AU - Dolinšek, J.
PY - 2007/6/6
Y1 - 2007/6/6
N2 - The isotope effect of hydrogen motion in an organic ferroelectric, phenazine (Phz)-chloranilic acid (H2ca and D2ca for normal and deuterated compounds, respectively) co-crystal, was studied by 35Cl nuclear quadrupole resonance (NQR). Besides a ferroelectric transition at Tc ≤ 253K (303K), a neutral-to-ionic transition was found below 170K (200K) for Phz-H2ca (Phz-D2ca). 1H-14N nuclear quadrupole double resonance measurements were also made in order to study the temperature dependent electronic state of Phz-(H/D)2ca. 14N NQR parameters suggested that donor orbital populations of the two nitrogen atoms in a phenazine molecule become nonequivalent (1.78 and 1.97) in the ferroelectric phase, while they are both equal to 1.89 in the paraelectric phase. In the ionic phase of Phz-D 2ca, which was obtained by cooling below 188K, they became 1.50 and 1.95, suggesting a proton transfer from D2ca toPhz.
AB - The isotope effect of hydrogen motion in an organic ferroelectric, phenazine (Phz)-chloranilic acid (H2ca and D2ca for normal and deuterated compounds, respectively) co-crystal, was studied by 35Cl nuclear quadrupole resonance (NQR). Besides a ferroelectric transition at Tc ≤ 253K (303K), a neutral-to-ionic transition was found below 170K (200K) for Phz-H2ca (Phz-D2ca). 1H-14N nuclear quadrupole double resonance measurements were also made in order to study the temperature dependent electronic state of Phz-(H/D)2ca. 14N NQR parameters suggested that donor orbital populations of the two nitrogen atoms in a phenazine molecule become nonequivalent (1.78 and 1.97) in the ferroelectric phase, while they are both equal to 1.89 in the paraelectric phase. In the ionic phase of Phz-D 2ca, which was obtained by cooling below 188K, they became 1.50 and 1.95, suggesting a proton transfer from D2ca toPhz.
UR - http://www.scopus.com/inward/record.url?scp=34248667026&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34248667026&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/19/22/226203
DO - 10.1088/0953-8984/19/22/226203
M3 - Article
AN - SCOPUS:34248667026
SN - 0953-8984
VL - 19
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
IS - 22
M1 - 226203
ER -