Pressure effect on the Curie temperature in Cr3□Te4 (quenching temperature 1000 °C) with the partially disordered phase of MLD and in Cr7□Te8 (1000 °C) with the disordered phase of MLD, and in Cr7□Te8 (400 °C) with the ordered phase have been supplementarily investigated by the electrical resistivity measurements and the magnetic induction method, in addition to the previous works. The shifting rates in TC with increase of hydrostatic pressures up to 5 kbar were determined as: dTC/dP = − (5.9 ± 0.1) deg/kbar and dTC/dP = − (6.3 ± 0.1) deg/kbar for Cr3□Te4 (1000 °C) by the magnetic induction and the electrical resistivity measurements, respectively, and dTC/dP = − (6.9 ± 0.4) deg/kbar for Cr7□Te8 (1000 °C), dTC/dP = − (5.3 ± 0.2) deg/kbar for Cr7□Te8 (400 °C) by the electrical resistivity measurements. Little difference in TC at atmospheric pressure and in the pressure effect on TC have been observed between Cr3□Te4 (1000 °C) and Cr3□Te4 (cooled slowly), unlike in the case of Cr7□Te8. The magnetic exchange interaction in the MLD‐type compound Cr1−δTe is also discussed.

We introduced benzenetoluene solution into the pores of the mesoporous silica material SBA-15 and investigated its fusion behavior using differential scanning calorimetry. On introduction into the pores, the concentration of the solution did not change. The introduced solution exhibited typical behavior of freezing-point depression upon the addition of a toluene component. We discuss this behavior and the large value of the slope of a plot of the fusion temperature of benzene in a confined sample against the logarithm of the molar fraction of benzene. Physical properties of a system confined in a nanometersized space differ from those of the bulk system owing to high interfacial tension and size-limited effects. 120 The physical properties are different from those of the bulk system. Thus, it is not known whether colligative properties, for example, freezingpoint depression or boiling-point elevation, or, in other words, the concept of classical thermodynamic mixing can be applied to such a system confined in a small space. However, it has been reported that this concept is applicable to first-order phase transitions of binary liquid crystals confined within pores. 21 In this study, we examined it in the case of a confined binary system that did not form a solid solution. A binary system that does not form a solid solution displays freezing-point depression when it is in the bulk state.The degree of freezing-point depression caused by doping with a second component is dependent on the entropy of mixing. Thus, the fusion temperature T fus of a solvent decreases linearly with an increase in the chemical potential of the solvent, namely, the logarithm of the reciprocal of the molar fraction of the solvent. The slope of the linear plot is proportional to the reciprocal of the entropy of fusion, ¦ fus S. However, in the case of a system confined in nanometer-sized pores, the ¦ fus S of the system probably differs from that of the bulk system. 1013 In addition, the size of crystals confined in such small pores is very small and we should consider the interfacial effect due to the large interfacial area. Fusion of the solvent in the solution proceeds gradually with an increase in temperature and with a reduction in the size of the crystals of the solvent. This can cause a new phenomenon, which has not been observed in bulk solutions.To investigate the physical behavior of a solution confined in a small pore, we must introduce the solution at any concentration into a pore. However, it is well known that some substances are preferentially confined in pores even if they are mixed well in solution. 22,23 We must choose a sample of an ideal solution that does not exhibit such an anomaly.We used a solution of benzene with a slight amount of toluene as a sample, which is a typical case of an ideal solution. The system does not form a solid solution and has a high T fus of benzene, which enables us to observe freezing-point depression.Firstly, we investigated whether or not this solution could be introduced into a pore at an...

We have used differential scanning calorimetry (DSC) to investigate the phase transition of a liquid crystal, N-(4-methoxybenzylidene)-4-butylaniline (MBBA), confined within porous silica materials with one- and three-dimensional pore architectures. Each phase-transition temperature of the confined MBBA linearly decreased with the inverse pore size compared with that of bulk MBBA. However, the degree of temperature shift varied owing to differences in the pore architectures. In addition, when MBBA was confined within one-dimensional pores, the thermal anomaly associated with the phase transition from the nematic phase to the isotropic liquid phase was not observed in the DSC measurements.

Shifts of the Curie temperature of a disordered and an ordered phase in Cr,nTe, including MLD have been investigated by magnetic induction measurements at hydrostatic pressures up to 5 kbar. The relative magnetization vanishes at the Curie temperature, TC = 343 and 332 OK for the disordered phase (lo00 "C) and the ordered phase (400 "C), respectively, at atmospheric pressure. The Curie temperature shifts to lower temperature with increasing

Rxagnetic induction and electrical resistivity of Cr3uTe4 including vacancies of magnetic atoms have been investigated in the vicinity of the Curie temperatures a t hydrostatic pressures up to 6 kbar. The magnetic induction smoothly vanishes at the Curie temperature, T, = 325 OK. The electrical resistivity shows a T-type anomaly with a kink a t 319 "K and atmospheric pressure, and this temperature is in agreement with the Curie temperature.The pressure effect on the Curie point has been obtained as: (dT,/dP) = -(6.2 f 0.4) deg/ kbar from the magnetic induction, and (dT,/dP) = -(5.9 1 0 . 3 ) deg/kbar from the electrical resistivity measurements. Although a large number of exchange chains are cut by the vacancies in CrJJTe,, only little difference has been observed in the Curie temperatures between CrTe and Cr,mTe4. This is not explained by a volume effect of exchange integral on the Curie temperature with dT,/dP < 0 in Cr,lJTe,, and a brief discussion of exchange interactions in this compound has been done in comparison with those in CrTe on the basis of the ionic model.Die magnetische lnduktion und die elektrische Leitfahigkeit von Cr,OTe,, das Leerstellen von magnetischen Atomen enthiilt, wurde in der Nahe der Curietemperatur bei hydrostatischen Drucken bis zu 6 kbar untersucht. Die magnetische Induktion verschwindet langsam bei der Curietemperatur T, = 325 OK. Die elektrische :Leitfahigkeit zeigt eine Anomalie vom r -T y p mit einem Sprung bei 319 "K und Atmospharendruck; die Temperatur stimmt mit der Curietemperatur uberein. Fur die Druckabhgngigkeit des Curiepunktes wurde aus Messungen der magnetischen Induktion (dT,/dP) = -(6,2 * 0,4) grd/kbar und der elektrischen Leitfahigkeit (dTJdP) = -(5,9 + 0,3) grdlkbar gefunden. Obwohl eine groBe Anzahl von Austauschketten durch die Leerstellen in Cr30Te, geschnitten werden, wurde nur eine geringe Differenz der Curietemperaturen von CrTe und Cr3UTe, beobachtet. Dies kann nicht durch einen VolumeneinfluB des Austauschintegrals auf die Curietemperatur mit dT,/dP < 0 in Cr3[7Te4 erklart werden. Eine kurze Diskussion der Austauschwechselwirkungen in dieser Verbindung wird in Vergleich zu der in CrTe auf der Grundlage eines Ionenmodells dnrchgefuhrt.