CAJ | 학술논문

通过液固界面上的溶解-沉淀耦合反应在Ba(NO3)2乙醇-水溶液中实现了毒重石晶型的碳酸钡在方解石(CaCO3)晶体基底上的外延生长，得到碳酸钡的单晶微米锥阵列。碳酸钡微米锥的长轴平行于毒重石晶体的[001]方向，同时也与方解石基底[001]晶向相同，其俯视图为六边形，具有近似的六方对称性。随反应时间的增加，外延生长形成的碳酸钡微米锥的尺寸增加，但其轴径比逐渐减小。通过改变乙醇-水混合溶剂中的乙醇含量或者Ba(NO3)2浓度也能调控碳酸钡晶体的尺寸和形貌。随着混合溶剂中乙醇含量与Ba(NO3)2浓度的提高，溶液中BaCO3的过饱和度增加，通过外延生长在方解石的(104)表面形成的BaCO3阵列结构的密集程度逐渐增加，尺寸逐渐减小，形貌从微米锥逐渐转变为微米柱状结构。经过对晶化过程及毒重石和方解石晶体结构分析，提出了在方解石表面外延生长形成的毒重石微米锥单晶阵列结构的形成过程机理：该过程为界面溶解-沉淀耦合反应的过程，方解石的溶解和毒重石的外延生长过程同时进行，由于两种晶体在方解石基底的(104)晶面与(001)晶面上具有中高度错配值，毒重石晶体在方解石的这两个晶面上发生Volmer-Weber型的外延生长，逐渐形成在靠近基底处包覆有方解石台阶的毒重石微米锥单晶阵列结构。
통과액고계면상적용해-침정우합반응재Ba(NO3)2을순-수용액중실현료독중석정형적탄산패재방해석(CaCO3)정체기저상적외연생장，득도탄산패적단정미미추진렬。탄산패미미추적장축평행우독중석정체적[001]방향，동시야여방해석기저[001]정향상동，기부시도위륙변형，구유근사적륙방대칭성。수반응시간적증가，외연생장형성적탄산패미미추적척촌증가，단기축경비축점감소。통과개변을순-수혼합용제중적을순함량혹자Ba(NO3)2농도야능조공탄산패정체적척촌화형모。수착혼합용제중을순함량여Ba(NO3)2농도적제고，용액중BaCO3적과포화도증가，통과외연생장재방해석적(104)표면형성적BaCO3진렬결구적밀집정도축점증가，척촌축점감소，형모종미미추축점전변위미미주상결구。경과대정화과정급독중석화방해석정체결구분석，제출료재방해석표면외연생장형성적독중석미미추단정진렬결구적형성과정궤리：해과정위계면용해-침정우합반응적과정，방해석적용해화독중석적외연생장과정동시진행，유우량충정체재방해석기저적(104)정면여(001)정면상구유중고도착배치，독중석정체재방해석적저량개정면상발생Volmer-Weber형적외연생장，축점형성재고근기저처포복유방해석태계적독중석미미추단정진렬결구。
Heteroepitaxial growth of single-crystal ine witherite (BaCO3) microcone arrays on the (104) face of calcite (CaCO3) was realized, by the interface-coupled dissolution-precipitation reaction in water/ethanol at room temperature. The witherite microcone long axis was parallel to the [001] direction of witherite and [001] direction of the calcite substrate. The top of the microcones appeared as uniform tri-symmetrical hexagons while the long axis of the witherite microcones was parallel to the electron beam. The witherite microcones increased in size and decreased in length:diameter ratio with extending crystallization time. The size and morphology of the epitaxially grown witherite could be tuned by changing the water:ethanol volume ratio, or the Ba(NO3)2 concentration of the precursor solution. Increasing the water:ethanol volume ratio or Ba(NO3)2 concentration yielded smal er, denser witherite single-crystal ine microstructures. The witherite microcone arrays were thought to form by the synergetic epitaxial growth of witherite and dissolution of calcite. Carbonate crystals of witherite and calcite contained middle-high misfits on calcite (104) and (001) faces. Witherite microcones may have grown epitaxially on these two calcite faces, according to the Volmer-Weber model.