Strain Tuning of Ferroelectric Polarization in Hybrid Organic Inorganic Perovskite Compounds

Abstract

Metal-organic frameworks (MOFs) are hybrid crystalline compounds comprised of an extended ordered network made up of organic molecules, organic linkers and metal cations. In particular, MOFs with the same topology as inorganic perovskites have been shown to possess interesting properties, e.g., coexistence of ferroelectric and magnetic ordering. Using first-principles density functional theory, we have investigated the effect of strain on the compounds C(NH2)3Cr(HCOO)3 and (CH3CH2NH3)Mn(HCOO)3. Here, we show that compressive strain can substantially increase the ferroelectric polarization by more than 300%, and we discuss the mechanism involved in the strain enhancement of polarization. Our study highlights the complex interplay between strain and organic cations' dipoles and put forward the possibility of tuning of ferroelectric polarization through appropriate thin film growing.

Raman‐scattering studies of pressure‐induced phase transitions in perovskite‐like acetamidninium manganese formate

“…The known formates have been extensively studied in a broad temperature range, and these studies showed that majority of them undergo phase transitions associated with orientational ordering of organic cations located in the cavities of the framework . Pressure is another thermodynamic parameter that can help to better understand structure–property relationship in this class of compounds . For instance, it has been shown that application of pressure may lead to enhancement of ferroelectric properties or its suppression .…”

“…For instance, it has been shown that application of pressure may lead to enhancement of ferroelectric properties or its suppression . Furthermore, application of pressure may lead to discovery of novel polymorphs that are not thermodynamically stable at ambient conditions . We have decided, therefore, to study high‐pressure behaviour of recently discovered acetamidinium manganese formate ([CH 3 C(NH 2 ) 2 ][Mn(HCOO) 3 ], AceMn), using Raman spectroscopy because this method is well‐known to be a very valuable tool in high‐pressure studies due to its sensitivity to changes in dynamics and structure of molecular units …”

Vibrational investigation of pressure‐ and temperature‐induced phase transitions in metal formates templated by ethylammonium ions

“…They are isostructural and crystallize at room temperature in the non‐centrosymmetric Pna 2 1 space group with ordered EtA + cations. Because the structure is polar, these compounds are possible ferroelectrics and EtAMn can be regarded as a multiferroic material . Interestingly, theoretical considerations showed that the ferroelectric polarization can be strongly increased by applying compressive strain .…”

Uniaxial Negative Thermal Expansion and Mechanical Properties of a Zinc-Formate Framework

“…Metal-formate frameworks (MFFs) have attracted considerable attention in the past decade due to their rich physical properties which include magnetism [1,2,3], ferroelectricity [3,4,5,6], negative linear compressibility [7], mechanical properties [8,9,10,11], and dielectricity [12,13]. Very recently, a few research groups have discovered that these MFFs can also exhibit large negative thermal expansion (NTE) properties [14,15,16,17,18].…”