Journal of Magnetism and Magnetic Materials 226 } 230 (2001) 101}102 Single crystal growth and de Haas}van Alphen e!ect of TmAl  T. Ebihara*, D. Aoki, Y. Inada, R. Settai, K. Sugiyama, Y. Haga, Y. Onuki Department of Physics, Faculty of Science, Shizuoka University, 836 Oya, Shizuoka 422-8529, Japan Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan Advanced Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, Japan Abstract We succeeded in growing single crystals of TmAl  with the AuCu  -type cubic structure. This compound is a reference foraheavy-fermioncompoundYbAl  .Thesinglecrystalsweregrownbytheself-#uxmethod.WeobserveddeHaas}van Alphen oscillation.  2001 Elsevier Science B.V. All rights reserved. Keywords: TmAl  ; Crystal growth; de Haas}van Alphen e!ect The rare earth compounds RX  (X: IIIb and IVb) crystallize in the AuCu  -type cubic structure. Recently, we observed the de Haas}van Alphen (dHvA) oscillation of YbAl  and clari"ed the Fermi surface properties. YbAl  is found to be a heavy-fermion compound with a large mass of 24m  , where the 4f electron becomes itinerant, forming a heavy conduction band [1]. TmAl  also crystallizes in the same crystal structure. The crystalline electric "eld (CEF) is as follows: two singlets (  ,   ),onenonmagneticdoublet(  )andthree triplets (  ,   ,   ) [2,3]. If the 4f electrons are localiz- ed, the topology of the Fermi surface is expected to be di!erent from that of YbAl  . To clarify the Fermi surface properties of TmAl  ,wetriedtogrowasinglecrystaland to observe the dHvA oscillation. The single crystals of TmAl  were grown by the self- #ux method [4]. The starting materials were 3N(99.9% in purity)}Tm and 6N}Al. The o!-stoichiometric amounts of Al and Tm in the atomic ratio 9:1 were put into the alumina crucible and set in the evacuated quartz-tube. The sample was heated up to 10003C and keptunder10003Cfor1h.Thetemperatureofthesample wasslowlycooleddownto7003Cwiththerateof153C/h, and then the heater was turned o!. An excess of Al surrounding the single crystals was removed by a NaOH solution. The single crystals with dimensions of about 112mm were grown in many numbers. * Corresponding author. The X-ray powder di!raction measurement was done to con"rm the crystallographic property. The peak positions and their intensities are well explained by theoretical calculations. The present single crystals were not found to contain another impurity phase. The de Haas}van Alphen (dHvA) study was also per- formed by the standard "eld modulation technique in high "elds up to 130kOe and at low temperatures down to 0.5K. Fig. 1 shows (a) the typical dHvA oscillation for the "eld along 100-direction and (b) its fast Fourier trans- formation (FFT) spectrum in low magnetic "eld. One fundamental dHvA frequency with 2.3210 Oe, which was denoted by d, was prominently observed. Fig. 2 shows (a) the typical dHvA oscillation for the "eld along 100-direction and (b) its fast Fourier trans- formation (FFT) spectrum in high magnetic "eld. As seen in Fig. 2(b), almost ten branches were observed in this "eld direction. Seven branches are fundamental ones with the dHvA frequencies F of 3.0210, 4.2910, 2.3010, 4.7010, 5.4410, 7.8010 and 1.0210 Oe. Here, F ("cS  /2e) is proportional to the extremal (maximum or minimum) cross-sectional area S  of the Fermi surface [5]. These branches were denoted by m, j, d, c, g, e and a, respectively. The 2d means the second harmonic of fundamental one. The d#c and a#c are the sum components of the funda- mental ones. Fig. 3 shows the temperature dependence of the d- branch's dHvA amplitude when the "eld was applied 0304-8853/01/$-see front matter  2001 Elsevier Science B.V. All rights reserved. PII:S0304-8853(00)01133-1