Show simple item record

dc.contributor.authorWestern, Arthur B.
dc.contributor.authorBaker, A. G.
dc.contributor.authorBacon, Charles R.
dc.contributor.authorSchmidt, V. Hugo
dc.identifier.citationA.B. Western, A.G. Baker, C.R. Bacon, and V.H. Schmidt, "Pressure-induced tricritical point in the ferroelectric phase transition of KH2PO4," Phys. Rev. B 17, 4461-4473 (1978).en_US
dc.description.abstractMeasurement of the net polarization charge of two KH2PO4 crystals as a function of temperature, applied electric field, and hydrostatic pressure indicates the existence of a tricritical point in the (2.3±0.3)-kbar pressure range. This result is based upon static measurements of the polarization response to applied dc field in a 0.5-K neighborhood of the ferroelectric transition at pressures of 0, 1, 2, 2.4, and 3 kbar. Unlike He3- He4 mixtures and some metamagnets, for KH2PO4 the field which gives rise to the "wing" structure of the tricritical point is experimentally available. For each of the five pressures the paraelectric region is well described by the Landau equation of state, E=A0(T−T0)P+BP3+CP5, to within 0.05 K of the transition temperature. The exponent δ derived from our data at 3 kbar is in the crossover region between the critical value of 3 and the tricritical value of 5 predicted by Landau theory. At 2.4 kbar our derived value of δ is consistent with the tricritical value of 5. Analysis of the data along lines of constant polarization, which are here called "isopols," indicates that the transition is first order at 0 and 1 kbar with the critical field decreasing from 183±60 V/cm at 0 kbar to 43±13 V/cm at 1 kbar. At 3 kbar the B coefficient is positive which indicates a second-order transition. This observation of a change in the order of the transition is supported by a change in the behavior of the isothermal dielectric susceptibility which has a maximum for E>0 at 0.5 kbar and at E=0 at 3 kbar.en_US
dc.subjectCondensed matter physicsen_US
dc.titlePressure-induced tricritical point in the ferroelectric phase transition of KH_{2}PO_{4}en_US
mus.citation.journaltitlePhysical Review Ben_US
mus.identifier.categoryPhysics & Mathematicsen_US
mus.relation.collegeCollege of Letters & Science
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.universityMontana State University - Bozemanen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.