TY - JOUR

T1 - Study on the pressure induced charge transfer phase transition in (C 5H11)4N(FeIIFeIII(C 2O2S2)3) by means of μsR spectroscopy

AU - Enomoto, Masaya

AU - Kida, Noriyuki

AU - Kojima, Norimichi

AU - Watanabe, Isao

AU - Suzuki, Takao

AU - Ishii, Yasuyuki

N1 - Funding Information:
The μSR measurements were supported by the KEK-MSL Inter-University Program for Oversea Muon Facilities and a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan .

PY - 2011/11/28

Y1 - 2011/11/28

N2 - We have investigated the magnetic properties of iron mixed-valence complexes, (n-CnH2n+1) 4N[FeIIFeIII(dto)3] (dto = C 2O2S2, n = 3, 5), in which not only a ferromagnetic transition but also a novel charge transfer phase transition (CTPT) take place [1]. This CTPT can be observed under ambient pressure for n = 3, while it appears abruptly above 0.5 GPa for n = 5 [2]. Recently, we have measured the muon spin relaxation (μSR) for the CTPT of n = 3, which revealed the dynamical process of electron-transfer between FeII and Fe III and its frequency was estimated at about 0.1 MHz [3]. To investigate the pressure induced CTPT for n = 5, we carried out the μSR measurement for n = 5 at 150 K between 0.30 and 0.64 GPa with the 4He gas-operated pressure system. The asymmetry of the muon spin relaxation for n = 5 with Cu-Be pressure cell was almost constant up to 0.55 GPa, while it rapidly decreased with increasing pressure above 0.60 GPa. This result shows that the applied pressure causes the spin fluctuation due to the CTPT, which induces the decrease of the asymmetry of muon spin relaxation. This experiment can correctly decide the phase transition pressure from the absence to the appearance of the CTPT for n = 5.

AB - We have investigated the magnetic properties of iron mixed-valence complexes, (n-CnH2n+1) 4N[FeIIFeIII(dto)3] (dto = C 2O2S2, n = 3, 5), in which not only a ferromagnetic transition but also a novel charge transfer phase transition (CTPT) take place [1]. This CTPT can be observed under ambient pressure for n = 3, while it appears abruptly above 0.5 GPa for n = 5 [2]. Recently, we have measured the muon spin relaxation (μSR) for the CTPT of n = 3, which revealed the dynamical process of electron-transfer between FeII and Fe III and its frequency was estimated at about 0.1 MHz [3]. To investigate the pressure induced CTPT for n = 5, we carried out the μSR measurement for n = 5 at 150 K between 0.30 and 0.64 GPa with the 4He gas-operated pressure system. The asymmetry of the muon spin relaxation for n = 5 with Cu-Be pressure cell was almost constant up to 0.55 GPa, while it rapidly decreased with increasing pressure above 0.60 GPa. This result shows that the applied pressure causes the spin fluctuation due to the CTPT, which induces the decrease of the asymmetry of muon spin relaxation. This experiment can correctly decide the phase transition pressure from the absence to the appearance of the CTPT for n = 5.

KW - Ferromagnetism

KW - Iron mixed valence complex

KW - Pressure induced charge transfer phase transition

KW - μSR

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U2 - 10.1016/j.poly.2011.03.019

DO - 10.1016/j.poly.2011.03.019

M3 - Article

AN - SCOPUS:82255175281

SN - 0277-5387

VL - 30

SP - 3137

EP - 3139

JO - Polyhedron

JF - Polyhedron

IS - 18

ER -